Margaret Thatcher was a very divisive figure in the UK, but not so across the Atlantic, where her popularity has endured decades after she left office. Why?
The candidates have been asked a playful question: If you're elected President, what would you want your Secret Service code name to be?
Christie: True Heart
Kasich: Unit One
Fiorina: Secretariat
Walker: Harley
Bush: Everready
Trump: Humble
Carson: One Nation
Rubio: Gator
Huckabee: Duck Hunter
Paul: Justice Never Sleeps
Cruz: Cohiba
Jeb Bush would put Margaret Thatcher on the $10 bill
Press AssociationCopyright: Press Association
Jeb Bush is probably going to regret this later: Asked which woman he'd put on the $10 bill, he responded "Margaret Thatcher." That's not an American!
Post update
Trump: "Autism has become an epidemic"
ReutersCopyright: Reuters
Mr Trump says he is pro-vaccine, but wants them administered over longer periods of time. He said he thinks giving babies vaccines can make them sick and lead to autism.
Ben Carson responded that Trump's assessment makes him "an OK doctor" and said there is no link to autism from vaccines.
Rand Paul agreed that people should be able to give children vaccines in smaller doses at once.
Quote Message: My husband Frank and I buried a child to drug addiction. So we must invest more in the treatment of drugs from Caryl Fiorina candidate
My husband Frank and I buried a child to drug addiction. So we must invest more in the treatment of drugs
The debate shifts to gun rights
"I think we need to do this state-by-state," Mr Bush says of gun control legislation, in contrast to calls for federal gun laws that would be applied uniformly to the states.
Is marijuana a major issue?
Rand Paul talks marijuana
Getty ImagesCopyright: Getty Images
"The war on drugs has had a racial outcome," said Rand Paul. States should decide for themselves what drugs are legal, he argued, and said it's not fair to want to put poor people in jail for smoking marijuana.
Bush on marijuana
APCopyright: AP
Quote Message: So 40 years ago, I smoked marijuana, and I admit it. My mom is not happy that I just (admitted this) from Jeb Bush Former Florida Governor
So 40 years ago, I smoked marijuana, and I admit it. My mom is not happy that I just (admitted this)
The candidates don't get to sit during the entire debate, but it's not just those on stage who are antsy.
Another view on foreign policy
APCopyright: AP
Quote Message: "There will always be a Bush or Clinton for you if you want to go back to war in Iraq from Rand Paul Senator
"There will always be a Bush or Clinton for you if you want to go back to war in Iraq
Existential Huckabee
APCopyright: AP
Quote Message: We can't afford another eight years of having a president who doesn't know what he doesn't know from Mike Huckabee Former Arkansas governor
We can't afford another eight years of having a president who doesn't know what he doesn't know
#FactCheck
GettyCopyright: Getty
Not so fast on that US Attorney factoid, Christie.
Donald Trump defends his lack of knowledge about "Arab names."
George W Bush 'kept us safe'
A huge applause has erupted in the auditorium after Jeb Bush said his brother kept America safe in the years following the attacks of September 11, 2001.
There's a bit of confusion about his responses, from viewers and Carson himself.
Different debates, different hosts
How do Fox and CNN compare?
Trump on taxes
Quote Message: I know people making a tremendous amount of money and paying virtually no taxes and it's not fair from Donald Trump candidate
I know people making a tremendous amount of money and paying virtually no taxes and it's not fair
APCopyright: AP
Who aren't we hearing from?
On Twitter, some note it's been a while since we've heard from Governor Scott Walker and Senator Rand Paul.
Executive v executive
Donald Trump and Carly Fiorina are trading jabs.
Mr Trump said he'd never let his opponent run one of his companies, while Ms Fiorina has said that her opponent filed for bankruptcy four times.
APCopyright: AP
About that New York Times ad...
Carly Fiorina maintains she performed well at HP, despite reports claiming otherwise. Here is the New York Times ad her defenders took out to hold up her name.
Rubio hits his stride with immigration
As immigration continues to dominate the Republican debate, Senator Marco Rubio has had a chance to step into the spotlight.
APCopyright: AP
Quote Message: My family are immigrants, my neighbors are immigrants from Marco Rubio senator
My family are immigrants, my neighbors are immigrants
The debate in Google searches
On the internet, five candidates are standing out among the pack of 11.
GoogleCopyright: Google
English v Spanish
"To have a country, we have to have assimilation," Mr Trump said, noting that to assimilate in the US immigrants have to learn English.
Mr Trump has repeatedly bashed Mr Bush for speaking Spanish on the campaign trail.
Early talk times
Like the first debate, Donald Trump is again leading the pack in talk time.
With the debate not even half-way over, praise for Carly Fiorina's performance is already pouring in on Twitter.
Post update
Awkward!
Carly Fiorina addresses Donald Trump's comments about her face made in Rolling Stone magazine. She said it sent a strong message to the women of America. He awkwardly responded that she "has a beautiful face and is a beautiful woman." She glared stoically onward.
Carly Fiorina is managing to respond to Jake Tapper's questions quickly, making her points clearly before running out of time. She garnered the loudest applause of the night after answering questions on the Iran Deal and Planned Parenthood.
Do the three senators share responsibility for Syria?
Trump says other candidates bear responsibility
Mr Trump said that the senators on the stage that voted against allowing President Obama to use greater force in Syria "absolutely" bear responsibility for conflict that is devastating the country.
ReutersCopyright: Reuters
Too close for comfort?
The candidates are quite cozy on the stage. We hope the air conditioning is blasting.
It's getting hot in here - and not because of the heat from the questions
When asked if President Obama should cancel an coming state dinner for China's President Senator Rand Paul said "I don't think we need to be rash... I think we need to leave lines of communication open."
Wisconsin Governor Scott Walker disagreed saying, it's "not just a visit. It's a a 21-gun salute...on the South Lawn" of the White House.
Jeb v Trump v Casinos
Some background information on what exactly happened with Trump and Bush and the casinos that never happened from CNN
Iran Deal
The Iran Deal has been raised in the debate.
Senator Ted Cruz of Texas said that if he were elected president, he "will rip to shreds this catastrophic Iranian deal".
Can hardly get a word in
The BBC's Rajini Vaidyanathan points out that some candidates have not had much of a chance to talk.
Trump and Putin - Friends?
Bush v Trump again
APCopyright: AP
Donald Trump denies that he tried to pay Jeb Bush off for casino gambling in Florida. Then tells him he likes that he is showing more energy tonight.
All of the candidates are vying to claim the mantle of being a political "outsider".
The idea of being a fresh face plays well in American politics - especially in the Republican party.
Chris Christie of New Jersey cited the fact that he was a Republican in a heavily liberal state, while Carly Fiorina took a slightly more poetic approach.
Google Trends has tracked the search traffic for the first four candidates - showing major spikes for Lindsey Graham. The search giant hasalso noted what the top search for each candidate. Lots of people want to know how old or tall the candidates are.
Hello America
The candidates are taking turns introducing themselves.
Donald Trump is already generating buzz by using the term braggadocious.
What are Bernie Sanders and Hillary Clinton up to?
Bernie Sanders is live-tweeting the debate. Hillary Clinton's team is fact-checking.
Rubio makes a joke
Marco Rubio made a reference to an infamous speech where he kept awkwardly grabbing for his water bottle
While this debate is between Republican candidates, the Democratic candidates are weighing in on social media.
Former Maryland Governor Martin O'Malley just tweeted his assessment of what to expect on Thursday.
Lindsey Graham stands out
Lindsey Graham's campaign is very pleased with his performance in the early debate. Some political reporters agree that he stood out and "won."
Candidates enter
The 11 candidates have taken to the stage and currently posing for images.
Pre-debate reading
If you haven't had a chance yet, be sure to read our preview of the debate - there's still about 10 minutes left.
Post update
Getty ImagesCopyright: Getty Images
Hello and welcome to the BBC's live coverage of the second Republican presidential debate.
Eleven of the Republican party's top contenders are squaring off at the Ronald Reagan Presidential Library in southern California, with real estate magnate Donald Trump both in the lead and preparing to come under attack.
We'll be updating this page in real-time with the big developments, fast analysis and the top trends across social media.
With just under a half-hour until the sparks fly, you can read our preview and prepare to be on the lookout for the following during tonight's debate:
Carly Fiorina's first main-stage performance, where sparks could fly between her and Donald Trump
Jeb Bush's attempts to be more lively and differentiate himself from the bombastic businessman
Increased scrutiny of Ben Carson who's popularity has risen since the last debate
Scott Walker to rebuild his popularity after a lacklustre debate performance last month
Live Reporting
Paul Blake, Ashley Gold and Tim Swift
All times stated are UK
View more on twitterView more on twitter 
APCopyright: AP - Christie: True Heart
- Kasich: Unit One
- Fiorina: Secretariat
- Walker: Harley
- Bush: Everready
- Trump: Humble
- Carson: One Nation
- Rubio: Gator
- Huckabee: Duck Hunter
- Paul: Justice Never Sleeps
- Cruz: Cohiba
Press AssociationCopyright: Press Association 
ReutersCopyright: Reuters View more on twitterView more on twitter 
APCopyright: AP 
Getty ImagesCopyright: Getty Images 
APCopyright: AP View more on twitterView more on twitter View more on twitterView more on twitter View more on twitterView more on twitter 
APCopyright: AP 
APCopyright: AP 
GettyCopyright: Getty View more on twitterView more on twitter View more on twitterView more on twitter 
GettyCopyright: Getty 
APCopyright: AP 
APCopyright: AP 
APCopyright: AP 
GoogleCopyright: Google View more on twitterView more on twitter View more on twitterView more on twitter View more on twitterView more on twitter 
APCopyright: AP View more on twitterView more on twitter View more on twitterView more on twitter View more on twitterView more on twitter 
ReutersCopyright: Reuters View more on twitterView more on twitter 
APCopyright: AP View more on twitterView more on twitter 
APCopyright: AP View more on twitterView more on twitter View more on twitterView more on twitter View more on twitterView more on twitter View more on twitterView more on twitter 
GoogleCopyright: Google View more on twitterView more on twitter - One minute to answer
- 30 seconds for rebuttals
Getty ImagesCopyright: Getty Images - Carly Fiorina's first main-stage performance, where sparks could fly between her and Donald Trump
- Jeb Bush's attempts to be more lively and differentiate himself from the bombastic businessman
- Increased scrutiny of Ben Carson who's popularity has risen since the last debate
- Scott Walker to rebuild his popularity after a lacklustre debate performance last month
Latest PostGoodnight!
That concludes our coverage of tonight's GOP debate. Be sure to stick with us throughout election season for updates and continued coverage.
Talk times updated
Love for the Iron lady
Margaret Thatcher was a very divisive figure in the UK, but not so across the Atlantic, where her popularity has endured decades after she left office. Why?
http://www.bbc.co.uk/news/world-us-canada-13365889
Secret Service code names
The candidates have been asked a playful question: If you're elected President, what would you want your Secret Service code name to be?
Jeb Bush would put Margaret Thatcher on the $10 bill
Jeb Bush is probably going to regret this later: Asked which woman he'd put on the $10 bill, he responded "Margaret Thatcher." That's not an American!
Post update
Trump: "Autism has become an epidemic"
Mr Trump says he is pro-vaccine, but wants them administered over longer periods of time. He said he thinks giving babies vaccines can make them sick and lead to autism.
Ben Carson responded that Trump's assessment makes him "an OK doctor" and said there is no link to autism from vaccines.
Rand Paul agreed that people should be able to give children vaccines in smaller doses at once.
Marathon men
...and his colleague...
Fiorina gets personal
The debate shifts to gun rights
"I think we need to do this state-by-state," Mr Bush says of gun control legislation, in contrast to calls for federal gun laws that would be applied uniformly to the states.
Is marijuana a major issue?
Rand Paul talks marijuana
"The war on drugs has had a racial outcome," said Rand Paul. States should decide for themselves what drugs are legal, he argued, and said it's not fair to want to put poor people in jail for smoking marijuana.
Bush on marijuana
Jeb and Cruz on SCOTUS
Take a deep breath and carry on
The candidates don't get to sit during the entire debate, but it's not just those on stage who are antsy.
Another view on foreign policy
Existential Huckabee
#FactCheck
Not so fast on that US Attorney factoid, Christie.
Left hanging
Talk times updated
Trump on "Arab names"
Donald Trump defends his lack of knowledge about "Arab names."
George W Bush 'kept us safe'
A huge applause has erupted in the auditorium after Jeb Bush said his brother kept America safe in the years following the attacks of September 11, 2001.
Who is winning on Twitter?
Jibes at Hillary
The elusive Ben Carson
There's a bit of confusion about his responses, from viewers and Carson himself.
Different debates, different hosts
How do Fox and CNN compare?
Trump on taxes
Who aren't we hearing from?
On Twitter, some note it's been a while since we've heard from Governor Scott Walker and Senator Rand Paul.
Executive v executive
Donald Trump and Carly Fiorina are trading jabs.
Mr Trump said he'd never let his opponent run one of his companies, while Ms Fiorina has said that her opponent filed for bankruptcy four times.
About that New York Times ad...
Carly Fiorina maintains she performed well at HP, despite reports claiming otherwise. Here is the New York Times ad her defenders took out to hold up her name.
Rubio hits his stride with immigration
As immigration continues to dominate the Republican debate, Senator Marco Rubio has had a chance to step into the spotlight.
The debate in Google searches
On the internet, five candidates are standing out among the pack of 11.
English v Spanish
"To have a country, we have to have assimilation," Mr Trump said, noting that to assimilate in the US immigrants have to learn English.
Mr Trump has repeatedly bashed Mr Bush for speaking Spanish on the campaign trail.
Early talk times
Like the first debate, Donald Trump is again leading the pack in talk time.
Post update
That face ...
Early praise for Fiorina
With the debate not even half-way over, praise for Carly Fiorina's performance is already pouring in on Twitter.
Post update
Awkward!
Carly Fiorina addresses Donald Trump's comments about her face made in Rolling Stone magazine. She said it sent a strong message to the women of America. He awkwardly responded that she "has a beautiful face and is a beautiful woman." She glared stoically onward.
More on Planned Parenthood
More on why Republicans want to defund the women's health organisation: http://www.bbc.co.uk/news/world-us-canada-33763503
Fiorina fits her points in, gets applause
Carly Fiorina is managing to respond to Jake Tapper's questions quickly, making her points clearly before running out of time. She garnered the loudest applause of the night after answering questions on the Iran Deal and Planned Parenthood.
How do you solve a problem like Iran?
BBC correspondents tweet:
Bernie and Hillary beg to differ
The candidates slam Planned Parenthood and commit to de-fund it. Over in non-GOP land, Clinton and Sanders beg to differ.
Memories of '90s
Big in Canada
#GOPDebate is also trending in Mexico right now.
Foreign policy is dominating...
...but the details don't seem to matter much
Do the three senators share responsibility for Syria?
Trump says other candidates bear responsibility
Mr Trump said that the senators on the stage that voted against allowing President Obama to use greater force in Syria "absolutely" bear responsibility for conflict that is devastating the country.
Too close for comfort?
The candidates are quite cozy on the stage. We hope the air conditioning is blasting.
It's getting hot in here - and not because of the heat from the questions
Moving on to China
Debate stays in foreign policy mode
When asked if President Obama should cancel an coming state dinner for China's President Senator Rand Paul said "I don't think we need to be rash... I think we need to leave lines of communication open."
Wisconsin Governor Scott Walker disagreed saying, it's "not just a visit. It's a a 21-gun salute...on the South Lawn" of the White House.
Jeb v Trump v Casinos
Some background information on what exactly happened with Trump and Bush and the casinos that never happened from CNN
Iran Deal
The Iran Deal has been raised in the debate.
Senator Ted Cruz of Texas said that if he were elected president, he "will rip to shreds this catastrophic Iranian deal".
Can hardly get a word in
The BBC's Rajini Vaidyanathan points out that some candidates have not had much of a chance to talk.
Trump and Putin - Friends?
Bush v Trump again
Donald Trump denies that he tried to pay Jeb Bush off for casino gambling in Florida. Then tells him he likes that he is showing more energy tonight.
Outsiders
All of the candidates are vying to claim the mantle of being a political "outsider".
The idea of being a fresh face plays well in American politics - especially in the Republican party.
Chris Christie of New Jersey cited the fact that he was a Republican in a heavily liberal state, while Carly Fiorina took a slightly more poetic approach.
Ben Carson's appeal
Read more about the outsider candidate: http://www.bbc.com/news/world-us-canada-34260966
Looking for a comeback
BBC reporters tweet:
Did he really just say that?
The reactions roll in to Trump's comments about Rand Paul's looks.
Trump v Paul
Rand Paul has called out Donald Trump for his personal attacks on others' appearances.
Mr Trump responded by telling the moderator, "I never attacked him for his look, and believe me, there's plenty of subject matter right there!"
Trump already a target
BBC's North America reporter tweets:
The Google 'vote'
Google Trends has tracked the search traffic for the first four candidates - showing major spikes for Lindsey Graham. The search giant hasalso noted what the top search for each candidate. Lots of people want to know how old or tall the candidates are.
Hello America
The candidates are taking turns introducing themselves.
Donald Trump is already generating buzz by using the term braggadocious.
What are Bernie Sanders and Hillary Clinton up to?
Bernie Sanders is live-tweeting the debate. Hillary Clinton's team is fact-checking.
Rubio makes a joke
Marco Rubio made a reference to an infamous speech where he kept awkwardly grabbing for his water bottle
Rules of the game
Ground rules for the debate
Democrats weigh in
While this debate is between Republican candidates, the Democratic candidates are weighing in on social media.
Former Maryland Governor Martin O'Malley just tweeted his assessment of what to expect on Thursday.
Lindsey Graham stands out
Lindsey Graham's campaign is very pleased with his performance in the early debate. Some political reporters agree that he stood out and "won."
Candidates enter
The 11 candidates have taken to the stage and currently posing for images.
Pre-debate reading
If you haven't had a chance yet, be sure to read our preview of the debate - there's still about 10 minutes left.
Post update
Hello and welcome to the BBC's live coverage of the second Republican presidential debate.
Eleven of the Republican party's top contenders are squaring off at the Ronald Reagan Presidential Library in southern California, with real estate magnate Donald Trump both in the lead and preparing to come under attack.
We'll be updating this page in real-time with the big developments, fast analysis and the top trends across social media.
With just under a half-hour until the sparks fly, you can read our preview and prepare to be on the lookout for the following during tonight's debate: