Republican presidential candidate, former Massachusetts Gov. Mitt Romney, from right, Rep. Michele Bachmann, R-Minn., and Virginia Gov. Bob McDonnell arrive at a campaign stop in Portsmouth, Va., Thursday, May 3, 2012. (AP Photo/Jae C. Hong)

Photo by: Jae C. Hong

Republican presidential candidate, former Massachusetts Gov. Mitt Romney, from right, Rep. Michele Bachmann, R-Minn., and Virginia Gov. Bob McDonnell arrive at a campaign stop in Portsmouth, Va., Thursday, May 3, 2012. (AP Photo/Jae C. Hong)