Nine Republican and six Democratic candidates will meet this week in their final debates before the lead off Iowa caucuses, and lively exchanges are all but certain.
The back-to-back debates - Republicans on Wednesday, Democrats on Thursday - come as both races in Iowa are toss-ups with just three weeks left before the voting begins.
On the Republican side,, a former Arkansas governor, has vaulted to the front-running position, overtaking longtime leader , a former Massachusetts governor, in a matter of weeks. The two are engaged in an increasingly fierce battle, with Romney assailing Huckabee on illegal immigration in a new TV ad. , the ex-senator of Tennessee who has dropped in polls, is looking to benefit from the two-way tussle in the final weeks of the campaign.
, the ex-mayor of New York, and Arizona Sen. aren't playing as aggressively as the others in the state, but will debate nonetheless. Republican congressmen of Texas, of Colorado and of California, and commentator Alan Keyes also said they will participate.
Among Democrats,, the yearlong front-runner in national polls, is locked in a three way race in Iowa with challengers , an Illinois senator, and , a former North Carolina senator. All three have added celebrities to their campaign schedules recently - media mogul Oprah Winfrey for Obama, former President Clinton for his wife, and actors Kevin Bacon and Tim Robbins are to join Edwards.
New Mexico Gov., and Sens. of Delaware and of Connecticut are looking to break into that top tier, and also will take part in the debate.
Sponsored by Iowa Public Television and The Des Moines Register, the two debates will be held in Johnston, Iowa, and broadcast live at 2 p.m. EST on Iowa Public Television, CNN, C-SPAN3, Fox News Channel, C-SPAN Radio and Fox News Radio.
Fox News has not previously aired a Democratic debate in this election cycle. Earlier this year, the Democratic candidates rejected Fox News' efforts to sponsor a debate after liberal groups and some of the candidates accused the Rupert Murdoch-owned network of being biased against Democrats.