McCain's running mates

Tim Pawlenty: The 48-year-old Minnesota governor and champion hockey player would be a youthful counterbalance to the 71-year-old McCain. Pawlenty showed loyalty by endorsing him when most analysts had written off his candidacy and he could boost the prospects of Republican victory in in his home state. Still, he may have hurt his chances this week by admitting on local radio that his wife would not have sex with him - although "she loves football" Photograph: Evan Vucci/AP

Mitt Romney: The former Massachusetts governor and Mormon venture capitalist clashed with McCain during the Republican primaries. But after Romney exited the race, he became a willing McCain surrogate, and he would address two issues that have nagged at McCain by bringing fundraising connections and religious appeal. While Romney may be the wisest choice on paper, it remains to be seen whether McCain can cool his famously bad temper and work alongside a former rival Photograph: Cheryl Senter/AP

Charlie Crist: This affable, moderate governor could kill off Democrats' chances of taking Florida. The state's voters have showered favourable approval ratings on Crist since he took office in 2007. His plan to limit state greenhouse gas emissions complements McCain's own focus on the issue. Perhaps Crist's biggest drawback is his bachelorhood, which has led some voters to ask uncomfortable questions about his sexuality Photograph: Mark Wallheiser/Reuters

Bobby Jindal: The newly elected Louisiana governor is the most surprising contender on McCain's shortlist. Ascending to lead his state after just three years in Congress, Indian-American Jindal's sharp intellect has wowed both McCain and the party. He would help McCain shed the Republicans' white male image. But choosing a 36-year-old newcomer would limit McCain's scope to attack Obama as inexperienced Photograph: Mario Tama/Getty

Rob Portman: He lacks the national profile of Romney or Crist, but this Ohio political veteran meets each of McCain's biggest needs. He is 53 but looks 10 years younger, he has appeal to conservatives, and he is popular in a swing state. Columnist Robert Novak, whose Republican connections are unrivalled, predicted a McCain-Portman partnership back in March Photograph: Scott J. Ferrell/Getty