SurveyUSA conducted a poll March 14-16 in which they asked voters if they would stick with John Mccain, Barack Obama or Hillary Clinton no matter who they picked as a running mate, or whether they would not be sure until they knew who the VP pick was. The pollster said that between 29 percent and 40 percent – depending on the state – said they were not sure if they’d vote for McCain without knowing his Number Two, while the ranges for Clinton and Obama are lower, (between 17 percent and 25 percent for Clinton, and between 12 percent and 28 percent for Obama). The SurveyUSA site has the state-by-state tables.