Michelle Obama has launched a stinging attack on US President Donald Trump as Democrats prepared to crown Joe Biden as their White House challenger.
"Donald Trump is the wrong president for our country," said the former US first lady in an emotional recorded message to the Democratic convention.
Disaffected members of Mr Trump's Republican party also piled in on him at the Democratic party conference.
The election takes place on Tuesday 3 November.
Because of the coronavirus outbreak, Democrats scrapped plans for a crowded party extravaganza with balloon drops and all the other political razzmatazz in Milwaukee, Wisconsin.
But it is unclear whether the largely virtual schedule of pre-recorded speeches with no live audience can generate the same level of enthusiasm as pre-pandemic gatherings of the party faithful.
Republicans will face the same challenge as they make their case for four more years in the White House at a drastically scaled-down convention next week.
What did Michelle Obama say?
Mrs Obama, who recorded her keynote address before Mr Biden announced his running mate, Senator Kamala Harris, six days ago, launched a blistering attack on Mr Trump.
"You simply cannot fake your way through this job," she said in remarks that closed the first night of the convention on Monday.
The headline speaker added: "Our economy is in shambles because of a virus that this president downplayed for too long."
"Stating the simple fact that a black life matters is still met with derision from the nation's highest office," Mrs Obama continued.
"Because whenever we look to this White House for some leadership, or consolation or any semblance of steadiness, what we get instead is chaos, division and a total and utter lack of empathy."
She said the last four years had been difficult to explain to America's children.
"They see our leaders labelling fellow citizens enemies of the state, while emboldening torch-bearing white supremacists.
"They watch in horror as children are torn from their families and thrown into cages, and pepper spray and rubber bullets are used on peaceful protests for a photo op."
Mrs Obama continued: "Donald Trump is the wrong president for our country. He has had more than enough time to prove that he can do the job, but he is clearly in over his head.
"He simply cannot be who we need him to be for us. It is what it is."
She described Mr Biden as a "profoundly decent man", touting the Democratic White House candidate's experience as vice-president under her husband, President Barack Obama.
"We have got to vote for Joe Biden like our lives depend on it," she said, wearing a necklace that said "Vote".
An emotional punch
A lot of politicians spoke at the camera during the "virtual" Democratic convention on Monday night. The only speaker who landed an emotional punch, however, was Michelle Obama.
The truth, she said, was that Donald Trump "simply cannot be who we need him to be for us".
"It is what it is," she said, employing the same words the president recently used about the coronavirus death toll - a jab that was as subtle as it was devastating.
She wasn't trying to convince Republicans to switch sides. That was the job of John Kasich, the Republican ex-governor of Ohio.
She wasn't trying to get left-wing progressives to rally to Biden. Vermont Senator Bernie Sanders handled that.
Mrs Obama was speaking to loyal Democrats, some of whom may have stayed at home or voted for a third party in 2016, some of whom may be dispirited or scared this year.
Her goal was to drive home the gravity of the moment and to give them a call to action.
What else happened on Monday?
The opening night of the convention, a two-hour programme hosted by former Desperate Housewives actress Eva Longoria Baston, was titled by party organisers "We the People".
John Kasich, who ran against Mr Trump for the Republican nomination in 2016, recorded a message calling on Americans to deny the president a second term in office.
Mr Kasich endorsed Mr Biden, saying: "We can all see what's going on in our country today and all the questions that are facing us, and no one person or party has all the answers.
"But what we do know is that we can do better than what we've been seeing today, for sure."
Bernie Sanders, the left-wing Vermont senator who was Mr Biden's fiercest competitor during the Democratic party's contest to pick a challenger to Mr Trump, also recorded a message.
He said: "My friends, I say to you, and to everyone who supported other candidates in this primary and to those who may have voted for Donald Trump in the last election: The future of our democracy is at stake. The future of our economy is at stake. The future of our planet is at stake."
He added: "Nero fiddled while Rome burned - Trump golfs."
Along with Mr Kasich, three other high-profile Republicans recorded messages for the convention's opening night: California businesswoman Meg Whitman, former New Jersey Governor Christine Whitman and former New York congresswoman Susan Molinari.
While their inclusion left the Biden team claiming a broad coalition, some Democrats grumbled that the Republicans used up precious time that could have benefited progressive speakers or lesser-known rising stars.
But Cedric Richmond, a Louisiana congressman and Biden campaign co-chairman, rejected that idea, saying, "remember tonight's theme is 'We the People,' not 'We the Democrats'".
The opening night also featured pre-recorded messages from everyday Americans, including repentant Trump voters and a woman who blamed her father's death from Covid-19 on the president.
How did President Trump hit back?
On Tuesday morning, Mr Trump responded to Mrs Obama's criticism in a series of tweets.
"[I] would not be here, in the beautiful White House, if it weren't for the job done by your husband," he wrote.
And on Monday, Mr Trump spoke to the BBC on Air Force One and lashed out at Mr Kasich. "He was a loser as a Republican, and he'll be a loser as a Democrat," the president said.
During a campaign speech earlier that day in Mankato, Minnesota, Mr Trump warned that if Mr Biden won in November, news outlets would lose their audiences.
"Nobody's going to want to cover sleepy Joe," Mr Trump said. "We will end up with one very boring socialist country that will go to hell."
Mr Trump also confirmed he would accept the Republican nomination for a second term during a live speech at the White House next week.
Democrats and some fellow Republicans have criticised the plan for using the White House as a campaign venue.
How will the rest of the Democratic convention play out?
The four-night jamboree will culminate in Mr Biden's speech on Thursday in a mostly empty ballroom in his home state of Delaware.
On Wednesday, his vice-presidential pick, Ms Harris, the daughter of immigrant parents from India and Jamaica, will accept her nomination as the first woman of colour to be a running mate on a major party presidential ticket.
Also speaking on Wednesday are former President Obama, Hillary Clinton, the 2016 Democratic nominee, and one of Mr Biden's former rivals, Senator Elizabeth Warren.
Tuesday will hear speeches from former President Bill Clinton and congresswoman Alexandria Ocasio-Cortez.
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