It's too soon to have a debate.
Candidates expected to participate include Rick Santorum, Tim Pawlenty, Herman Cain, Ron Paul, Gary Johnson and possibly Jon Huntsman.
Johnson is more of a "libertarian" like Ron Paul. Huntsman was recently Obama's ambassador to China. He praised Obama and Hillary.
Of these candidates, the most conservative are probably Cain and Santorum. They're probably also the most supportive of Israel of this group.
I don't thnk any of the above mentioned candidates will likely get the nomination.
The two people who need to be challenged are Romney and Daniels. Romney raises a lot of money from establishment groups and Daniels is is popular among the establishment.
Huckabee's supporters should be annoyed at Pawlenty. He stole one of Huckabee's campaign managers from the 2008 campaign in Iowa.