Research 2000's latest poll test South Dakota Republican Sen. John Thune against two of his strongest potential rivals, Rep. Stephanie Herseth Sandlin and former Sen. Tom Daschle (who Thune defeated by a very narrow margin in his first successful bid for the Senate back in 2004).
The numbers indicate that no Democrat is likely to beat Thune in 2010.
Research 2000 for Daily Kos. 3/30-4/1. Registered voters. MoE 3.9%.
John Thune (R) 53
Tom Daschle (D) 40
John Thune (R) 51
Stephanie Herseth Sandlin (D) 39
Pretty similar numbers...and given the relatively high profiles of Daschle, a three-term Senator and former Senate Majority Leader, and Herseth Sandlin, the state's sole Representative in the House, that's fairly significant.
Thune starts over 50% against both of them, and his favorables are good. Overall, solid numbers for the incumbent, who should escape a really strong challenge in 2010.
Thune's numbers are close enough to the 50% line that it's theoretically possible he could be defeated, but it would take an even worse political climate for Republicans, and a lot of luck for whatever Democrat did sign on.
Herseth Sandlin is expected to run for Governor (and she will probably win), and Daschle is almost certainly done with electoral politics. It is possible that a little-known state legislator might step up and provide a decent kamikaze challenge...but it's far more likely that Democrats won't waste their time here, and Thune will cruise to a second term.