A new PPP poll in Colorado's U.S. Senate race finds that Andrew Romanoff would beat Jane Norton 44-39, while Norton and Michael Bennet are tied at 43. This is similar to the advantage suggested by several recent Rasmussen polls, suggesting that whatever effect they're finding, it isn't just a result of Rasmussen's peculiar polling methodology.
As Nate Silver notes, PPP has a "house effect" of 1.4 percentage points in the GOP direction, while Rasmussen's is 5.5 points toward the GOP. This doesn't mean that one is more correct -- we don't really know what the 2010 electorate will look like yet -- just that Rasmussen has reported consistently more favorable numbers for the GOP. So the top line numbers on these polls are somewhat inconsistent with each other. Nonetheless, both find a consistent advantage for Romanoff.
RedGreen wisely cautions us that Romanoff's advantage could quickly vanish should he become the nominee. After all, the GOP is currently criticizing Bennet and ignoring Romanoff, which would change quickly. Nonetheless, Romanoff has some healthy numbers on his side going into next week's caucuses.