Rick Perry said he wants to be the Tim Tebow of the Iowa caucuses.At Thursday's debate in Iowa -- the last before voters in the state vote Jan. 3 -- Perry said that, like the Denver Broncos quarterback, he's been underestimated."There are a lot of folks that said Tim Tebow wasn't going to be a very good NFL quarterback," Perry said. "There are people who said he didn't have the right throwing mechanism, or that he doesn't play the game right. And he won two national championships. And that looked pretty good. And we're national champions of job creation back in Texas."Perry promised to make a late 4th quarter comeback."Let me tell you, I hope I am the Tim Tebow of the Iowa caucuses," Perry said, to applause and laughs.Perry has struggled in the debates, and in one he paused awkwardly, unable to remember the third federal agency he would dismantle if elected.But he said Thursday night he's "kind of getting to where I like these debates."Perry said if he becomes the GOP nominee, he and Democratic President Barack Obama "will get it on."