Mitt Romney will launch a four-state bus tour through Virginia, North Carolina, Florida and Ohio on Saturday, his campaign announced Monday afternoon.


The announcement set off a firestorm of speculation Romney could announce his running mate during the tour. The only time indication the Romney campaign has given is to say the VP announcement will come before the Republican national convention begins, in Tampa on Aug. 27. 

All four stops on the bus tour are critical swing states that Romney likely needs to carry if he's going to win the presidency.

The "Romney Plan For A Stronger Middle Class" bus tour will start in Virginia on Saturday and roll south to North Carolina, then stop in Florida for a day before jumping over to Ohio next Tuesday.