Republican presidential hopefuls meet in Florida on Monday for another debate that is likely to see front-runners Rick Perry and Mitt Romney jockeying for the lead.
The debate sponsored by CNN and the Tea Party Express will focus on jobs and the economy, as well as Social Security.
Here is a look at the major Republicans candidates seeking for the nomination and the opportunity to face Democratic President Barack Obama in the November 2012 election.
RICK PERRY (March 4, 1950)
The three-term Texas governor was second in most polls even before announcing that he would enter the race and has shot to the top since jumping into the fray in August.
Perry is seen as a candidate who might bridge a divide within the party between conservatives unexcited about Romney and those who see another Tea Party favorite, Michele Bachmann, as unelectable.
While Perry would have the advantage of being the field's only governor from the South, a powerful party stronghold, he inevitably will draw comparisons with another Texan: former President George W. Bush. Bush's lasting unpopularity could pose a hurdle in a general election.
Critics question Perry's economic record. They say many Texas jobs he claims credit for creating are low-wage and his record includes heavy education cuts, low public service levels and high numbers of people without health insurance.
MITT ROMNEY (March 12, 1947)
Romney, who lost the nomination to John McCain in 2008, had topped polls of potential Republican candidates by an average of about 5 percentage points until Perry entered.
Romney still leads the Republican money race, raising about $18 million in the second quarter of 2011, more than four times as much as any other contender. Perry has not released fund-raising figures yet.
Romney co-founded private equity firm Bain Capital and has touted his business experience as a way to attack Obama's handling of the struggling U.S. economy. Critics say he was a corporate raider who cut jobs.
While favored by pro-business Republicans, Romney is viewed skeptically by some conservatives because he was governor of liberal Massachusetts and is a Mormon, a religion some evangelicals do not consider Christian.
Republicans have attacked him because of a healthcare plan he helped develop in Massachusetts that became a model for the Obama healthcare law. Romney defends the state law and attacks the federal version, and has promised to repeal Obama's plan.
MICHELE BACHMANN (April 6, 1956)
A leader of the Tea Party movement, Bachmann joined the upper tier of candidates after a strong performance in the first major Republican debate in June.
But once Perry entered the race, Bachmann faded, delivering a less-than-forceful performance in a debate in California this month and falling in the polls.
She won the Iowa straw poll in August and remains competitive in the state, where social conservatives are strong. She might struggle in primaries in New Hampshire and Florida, where her strong religious views and uncompromising positions on financial issues may not appeal to more moderate Republicans.
JON HUNTSMAN (March 26, 1960)
He annoyed the White House by resigning in April as Obama's ambassador to China when he was weighing a run for the Republican presidential nomination.
Like Romney, Huntsman is a Mormon. The former governor of Utah and member of a wealthy chemicals family is a moderate, which could make it hard for him to win over conservatives, who play a big role in the nominating process.
Huntsman's name recognition is low and his biggest immediate hurdle among Republican voters is his service to the Obama administration. He lags far behind in opinion polls.
RON PAUL (August 20, 1935)
An anti-war congressman from Texas who ran unsuccessfully for the party's 2008 nomination, libertarian Paul, 75, is known as the intellectual godfather of the Tea Party.
His calls for steep cuts in the federal deficit and the size of government have moved to the mainstream of debate in Congress since November when the fiscal conservative movement swept Republicans back into power in the House.
NEWT GINGRICH (June 17, 1943)
The former speaker of the House of Representatives was the main architect of the 1994 Republican congressional election victory and author of the Contract with America political manifesto. Gingrich ended his 20-year congressional career after Republican losses in 1998 elections.
Leading members of Gingrich's campaign team resigned in June, and he has had a poor showing in opinion polls.
RICK SANTORUM (May 10, 1958)
Santorum, once a leading Senate Republican, was badly defeated in his 2006 re-election bid.
He made a name for himself opposing abortion rights and gay marriage while backing welfare reform. He has campaigned hard to enhance his profile in early voting states but remains far back in the Republican field.
HERMAN CAIN (December 13, 1945)
A radio talk show host and former chief executive officer of Godfather's Pizza, Cain was chairman of the Federal Reserve Bank of Kansas City's board of directors and has never been elected to political office.