Republican presidential candidates spent a substantial part of Thursday night's debate clarifying former positions, in some cases defending controversial policies or statements and in some cases denying that they ever occurred.

Texas Gov. Rick Perry did not attempt to run away from his decision to offer in-state tuition to Texan immigrants who had arrived in the country illegally as children, offering an impassioned defense of the policy over a chorus of boos from the audience. Perry's rivals have repeatedly attacked him for the legislation, but he has never wavered in defending it.

If you say that we should not educate children that have come into our state for no other reason than that they've been brought here by no fault of our own, I don't think you have a heart, Perry said.

Inconsistency In The Air

Other candidates were not so consistent. Perry criticized former Massachusetts Gov. Mitt Romney for supporting Race to the Top, a federal program in which states competed for education funding by striving to pursue education reforms embraced by the Obama administration. Romney responded that I don't support any program [Perry]'s describing. But that contradicts comments Romney made embracing the program during a townhall meeting in Miami.

I think Secretary Duncan has done some good things, Romney said then. I hope that's not heresy in this room.

At the previous presidential debate Rep. Michele Bachmann, R-Minn., lambasted Perry for pushing legislation that would have vaccinated young Texan girls against the human papilloma virus, cautioning that the vaccine was dangerous and in subsequent interviews describing an encounter with a woman whose daughter suffered mental retardation after using the vaccine. Health officials dismissed the claim, pointing out that there is no evidence to link the vaccine to mental retardation. On Thursday, Bachmann denied outright having suggested the vaccine is dangerous.

I didn't make that claim nor did I make that statement, she said.