Profile: Rahm Emanuel
Rahm Emanuel's appointment as chief of staff to President Barack Obama came after a long period as a powerful player in the Democrat party.
A strategist and fundraiser in his early years, he spent six years as a congressman before becoming the president's right-hand man.
Mr Emanuel, 50, has a reputation for a tough and aggressive style in the political arena, and has been dubbed "Rahmbo" by some in the US media.
His abrasiveness has been the cause of negative news reports in the time since his appointment.
But it was another member of his family who caused him difficulty soon after he took up the job.
Mr Emanuel had to disavow himself from comments made by his father to an Israeli newspaper. Benjamin Emanuel managed both to suggest that his son would have a pro-Israeli bias and at the same time offending Arabs, saying: "Obviously he'll influence the president to be pro-Israel. Why wouldn't he? What is he, an Arab? He's not going to be mopping floors at the White House."
Controversy struck again when the chief of staff was reported to have sworn and referred to some liberal activists as "retarded" in a private meeting.
The remark drew fire from disabled groups as well as Sarah Palin.
There was also negative coverage in March 2010 when Democrat Congressman Eric Massa complained that Rahm Emanuel had approached him in the gym showers, while naked, and harangued him over a budget vote.
"Do you know how awkward it is to have a political argument with a naked man? ... It's ridiculous," Mr Massa said.
The role of the chief of staff is a vital one, acting as the president's most senior adviser, counselling him and attempting to get his proposals passed by Congress. He also guards the door to the Oval Office and needs to be able to say "no" when the president needs him to.
Some Washington observers have portrayed Mr Emanuel as the "bad cop" to Mr Obama's "good cop".
Mr Emanuel graduated from Sarah Lawrence College in New York in 1981 after turning down a dance scholarship. He received his Masters in Speech and Communication from Northwestern University in 1985. He launched his political career at consumer rights organisation Illinois Public Action.
He has had a rapid rise up the party hierarchy since his election in 2002 as congressman for Illinois' Fifth District in Chicago.
In his second term Mr Emanuel served on the House Ways and Means Committee, which is responsible for overseeing taxes, trade, Social Security and Medicare issues.
He was appointed to serve as Chairman of the Democratic Congressional Campaign Committee in 2006.
Under his leadership, the Democrats gained 30 seats in the House of Representatives, allowing them to gain control of the House after 12 years of Republican control.
In 2007, he was elected to serve as the Democratic Caucus Chair, the fourth highest ranking Member of the House Democratic Leadership.
Stories of Mr Emanuel's focus and determination are widespread around Washington and Chicago, and he has developed a reputation as an aggressive operator.
He once confessed to the Chicago Tribune that he was acutely aware of how others thought of him: "I wake up some mornings hating me too," he told the newspaper.
A practising Jew, Mr Emanuel's Israeli heritage has prompted positive headlines in Israel, where some were concerned earlier in the election campaign about the likely direction of Mr Obama's Middle East policy.
The prospective chief-of-staff himself volunteered to serve in Israel's army during the first Gulf War of 1991 - rust-proofing brakes in northern military bases, Israeli media reports.
Back in the US, Mr Emanuel became the director of finance for Bill Clinton's presidential campaign in 1992.
He then went on to serve as a senior adviser to President Clinton from 1993 to 1998 - first as an assistant to the president for political affairs and then as senior adviser for policy and strategy.
After his time in the Clinton administration, Mr Emanuel became a managing director for a leading global investment bank in Chicago, reportedly earning $16m.
Mr Emanuel worked on Paul Simon's 1984 US Senate election and served as an adviser and chief fundraiser for Chicago Mayor Richard M Daley in 1989.
When Mr Daley recently said he would stand down, speculation immediately started that Mr Emanuel would run to replace him, having privately said that mayor of Chicago was a dream job.
A dedicated family man with a wife, Amy, and three young children, one of Mr Emanuel's main considerations in choosing whether to run for mayor will be the effect of uprooting his family from Washington.