Republican and Conservative political analysis and commentary

Why does Fred Thompson have a bigger lead in the Rasmussen poll than other polls?

Rasmussen's recent polls have had Thompson up by seven to 10 points, while other recent polls have Thompson second to or virtually tied with Rudy Giuliani. Jim Geraghty at National Review's blog "The Corner" decided to ask Scott Rasmussen to explain. The short answer: As a poll respondent pool gets more selective, Thompson’s support grows.

"Every poll has seen Fred Thompson gaining ground, so that’s a common point among all the polls,” Rasmussen said. “We are only group that’s doing any kind of a screen to determine who is likely to vote in a primary. It’s not just on all adults, not just on registered voters. When you include people not following the race closely, the candidate with the biggest name ID is going to win out. The tighter you draw the screen on your pool of respondents, the better Thompson performs.”

Rasmussen told Geraghty that the GOP primary right now is very fluid.

“Twenty percent are saying they’re not sure who they’re going to vote for, and nobody is reaching thirty percent. There are two sets of numbers that are particularly bouncing. When Thompson goes up, Romney goes down a little bit; they’re playing for the conservative semifinals. Then you’ve got Rudy and McCain, who are playing for the moderate semifinals, and McCain is bouncing back a little bit lately. So my sense is this race is waiting for somebody to grab a hold of it and take control. Giuliani is perceived by Republicans to be most electable, Thompson is perceived as most conservative, and Romney is leading the early states. Ordinarily, all three of those would be a sign of being the frontrunner.”

A key number right now is that, no matter who is in the field, Giuliani is stuck at around 30-35 percent and has been for awhile. The anti-Rudy vote is two-thirds of the GOP electorate, but those votes are, so far, scattered across several candidates including Romney, McCain, Thompson and also Mike Huckabee and the rest of the field. Once a candidate behind Giuliani begins to consolidate the anti-Rudy vote, it will cascade toward that person and they will win the nomination.

Right now, it looks like Thompson has the best shot at that given that he's already tied with Rudy, or slightly ahead if you trust Rasmussen's numbers and methodology. Giuliani has been running for almost a year and his name recognition dwarfs Thompson's, suggesting Fred has significant upside potential.

As either McCain or Romney fades, look for most of their support to go to Fred, not Rudy - despite Rasmussen's characterization of McCain as being in the "moderate semifinals" with Rudy.

Prediction: The GOP race will, clearly, be a two-person race by Thanksgiving.