I'll update this as the debate goes along. Add your thoughts in comments.
Update (7:20): On the question of whether the invasion of Iraq was right or wrong, Mitt Romney dodged, Rudy Giuliani was straight forward and said he supported it; Duncan Hunter said he would use tactical nukes against Iran to prevent them from developing a nuke themselves. Rudy agreed.
Ron Paul went right to his cut and run rhetoric.
Update (7:41): John McCain failed to explain himself with the immigration bill. McCain said it wasn't the bill he'd have written. Huh?
Hunter called the bill the Bush/McCain/Kennedy bill. That'll leave a mark.
Giuliani harped on the lack of a database and Romney suggested making the Z-Visa temporary.
Update (8:06): On pardoning Scooter Libby, Giuliani, Tommy Thompson, Romney and Tom Tancredo said they would comsider it as did huckabee. Others dodged.
Hunter said he would pardon Border Patrol agents Compion and Ramos who were jailed for shooting a drug dealer. That will go over well with conservatives.
Update (8:29): Giuliani hit the prescription drug question out of the park. He also dealt well with the Iraq question.
Sam Brownback said twice he'd introduce legislation tomorrow to break Iraq into three "states." An interesting concept I'll cover tomorrow.
Update (8:37): Ron Paul actually just said that Iran is not a threat in response to Duncan Hunter's earlier assertion that he would preemptively nuke Iran to keep them from obtaining nukes. He also said (and I paraphrase) that they've never done anything to us. I'm sure there are people who were hostages for 444 days who would beg to differ, congressman.
Paul is not a libertarian or Republican, he is an anti-war liberal.