I can only think of one Republican that seems like he could handle being a candidate for President that could do the job if winning the seat.
http://hagel.senate.gov/
I cant honestly think of anyone else who would make a candidate that would be palatable, does anyone know of a Republican that would be an effective candidate? Not Brownback of Kansas, either, if he is not living in full blown wingnuttville he lives in its suburbs. Peronally I think he lives in the city center, along with all the others who screamed over stopping funding for stem cell research.