The US senator from South Dakota was a hero to many Republicans for defeating then-Senate majority leader Tom Daschle in 2004. He’s a solid conservative with movie-star good looks who would give a Romney-led ticket some regional diversity. Senator Thune is probably not as likely a choice as some others – and it’s not clear if he would be interested in the job – but he’s a solid candidate on many counts.

Charles Dharapak/AP
Sen. John Thune (R) of South Dakota speaks about the Keystone XL pipeline during a news conference on Capitol Hill in Washington on March 22.