| SIMI VALLEY, California
SIMI VALLEY, California Ten Republican White House contenders, led by early favorites Rudolph Giuliani and John McCain, will crowd the stage on Thursday for a first debate likely to be dominated by the unpopular Iraq war.
A week after the Democratic candidates held their opening debate but more than 18 months before the November 2008 election, the Republicans take their turn in the political spotlight beginning at 5 p.m. PDT (midnight GMT) at the presidential library of conservative Republican hero Ronald Reagan outside Los Angeles.
The leading Republican contenders have backed President George W. Bush on the war and support his increase in troop levels in Iraq, with McCain leading the charge to a degree that his campaign has become tied to the war effort.
While polls show the war is increasingly unpopular with most Americans, they also show Republican primary voters, who could decide the White House nomination, still support it.
Giuliani, the former mayor of New York who has led Republicans in national polls for months, and McCain, an Arizona senator who was an early favorite but has struggled of late, are well-known political commodities.
But the rest of a largely unknown Republican field will be looking to introduce themselves.
The debate offers an early opportunity for candidates like former Massachusetts Gov. Mitt Romney, whose strong fund-raising and establishment support have put him in the race's top tier even as he lingers in single digits in the polls.
"For a lot of people watching, this is their first chance to go comparison shopping with 10 different candidates," said Romney spokesman Kevin Madden. "Our goal right now is to introduce ourselves to the American public and introduce the governor's ideas."
Also participating will be Kansas Sen. Sam Brownback, Reps. Tom Tancredo of Colorado, Ron Paul of Texas and Duncan Hunter of California, and three former governors -- Mike Huckabee of Arkansas, James Gilmore of Virginia and Tommy Thompson of Wisconsin.
The Republican presidential field has sparked some dissatisfaction among activists, particularly conservatives, and two well-known Republicans are waiting to decide whether to jump in the race.
Former House Speaker Newt Gingrich says he will make a decision in September. Fred Thomson, a former actor turned senator who went back to acting again, is expected to decide by early summer.
Thompson, however, is giving his first big political speech on Friday night to a conservative group in nearby Orange County, south of Los Angeles.
Thursday's 90-minute debate will be televised on cable channel MSNBC and co-sponsored by Politico.com, which has invited questions that could be posed to the candidates.
Democratic presidential contender John Edwards, the party's 2004 vice presidential nominee and an opponent of the Iraq war, submitted a question on Wednesday. He asked the candidates: "Has the Bush doctrine of a global war on terror backfired?"
Giuliani, while leading in the polls, has drawn criticism from some conservatives for his liberal stances in support of gay rights and abortion rights. Romney has been attacked for changing his views and adopting more conservative stances.
But none of the candidates will have a lot of time, with the campaigns expected to have about seven to 10 minutes speaking time.