Tough, photogenic and conservative, Thune is also a rising star in the Republican Party, having unseated then majority leader Tom Daschle in the South Dakota senatorial race in 2004 and becoming part of the party leadership in the Senate while still in his first term. He earned a reputation for independence after fighting Bush over base closings but remains very popular with the GOP élite for his social and fiscal conservatism. However, he's nationally unknown and would be another Senator on the ticket, making him a long shot.
by Massimo Calabresi, with reporting by James Downie/Washington