the republican candidates take the stage in this, their last face-off before the florida primarily. i ll moderate tonight s republican debate right here on cnn. everyone s talking about the tension on the tarmac. in your face airport encounter between arizona s republican governor. what was that all about? and newt gingrich vows to establish a permanent colony on the moon. will that idea take off with voters? i m wolf blitzer on the campus of the university of north florida in jacksonville. you re in the situation room. just four hours from now, the four remaining republican candidates will square off right here in jacksonville. it s the final debate before next tuesday s crucial florida primary. it s become a grudge match between the front-runners, mitt romney and newt gingrich. our chief analyst gloria borger is here and jim acosta has been covering this campaign. jim. let me start with you. it looks like romney may try to go to the jugular. somebody may go to t