Gov. Rick Perry, R-Texas, appears doomed to a fifth-place finish in Iowa. Unless he drops out, that would make South Carolina his last stand against Republican frontrunner Mitt Romney.

The problem is that he might not receive an invitation to an upcoming South Carolina debate (given the debate criteria).

Candidates can qualify to participate in the CNN/Southern Republican Leadership Conference debate January 19th (two days before the South Carolina primary) in one of four ways. First and second, they can place in the top four in either Iowa or New Hampshire. Third and fourth, they can qualify by averaging seven percent support in three polls conducted nationally or in South Carolina by certain approved media and polling organizations.

Either Newt Gingrich or Rick Perry, it appears, will receive the debate invitation that comes with a fourth place finish in Iowa. With 31 percent of precincts reporting, Gingrich is in fourth place (13 percent) and Perry is in fifth place with ten percent support.

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The stakes are higher tonight for Perry than for Gingrich. Perry has struggled in recent polls, and a poor finish in Iowa will not give him a ratings boost. Gingrich, by contrast, has 23 percent in a Gallup tracking poll concluded on January 2nd, so he may qualify for the debate just on the strength of his polling support, no matter what happens in Iowa.

Respondents in that same Gallup poll gave Perry only seven percent support -- just at the threshhold for debate qualification. Average that number with polls conducted after the Iowa caucuses, and Perry's odds could be long.

Perry is skipping New Hampshire, heading straight to South Carolina after the Iowa caucuses. If he doesn't catch fire in the polls quickly, he may miss the upcoming debate -- and find it much more difficult to spread his message to South Carolina voters.