Age: 40
Occupation: U.S. Senator
Young and charismatic, Rubio burst onto the scene in 2010 when he won a Florida Senate seat by trouncing then Governor Charlie Crist, a moderate Republican who turned independent when it was obvious Rubio would defeat him in the party's primary. A shrewd and dynamic campaigner, the Cuban-American Rubio rode the gushing support of the right-wing Tea Party while keeping it at a safe distance. Oft mentioned as the GOP's strongest vice-presidential pick, he may find that his biggest challenge might be to not outshine the nominee.