Sen. Jim DeMint (R-S.C.) will head to Kansas next week to stump for the Senate campaign of Rep. Jerry Moran (R-Kan.). Moran is locked in a primary race with fellow Rep. Todd Tiahrt (R-Kan.) in the race for Sen. Sam Brownback's (R) open Senate seat.

All of the public polling in the race thus far has shown Moran solidly in the lead. A Survey USA poll released earlier this week had Moran up 20 points. But Tiahrt's campaign is trumpeting an internal poll it says shows the race close, as well as endorsements from former Alaska Gov. Sarah Palin, Karl Rove and talk radio host Sean Hannity.

And with DeMint on one side of this primary and Palin on the other, the race pits two of the most active GOP surrogates this season against one another. Moran won DeMint's backing last September. Palin endorsed Tiahrt in June. Both have weighed in on a number of Republican primaries this year.

DeMint also has a campaign stop planned in Colorado next week for prosecutor Ken Buck (R), who's facing former Lt. Gov. Jane Norton (R) in the state's Aug. 10 primary.