This is your open thread for the first of two debates in the next 12 hours.

Mitt Romney, as the leader by 20-plus points has to most to lose tonight. Ron Paul, Rick Santorum, and Newt Gingrich have the most to gain. It will be interesting to see if Rick Perry’s heart is really still in this race or if he has another disastrous debate. Finally, tonight is one of two final chances, tomorrow’s debate being the last, for Jon Huntsman to show any relevance whatsoever in the Republican primary.