** FILE ** House Budget Committee Chairman Rep. Paul Ryan, R-Wis. introduces Republican presidential candidate, former Massachusetts Gov. Mitt Romney before Romney spoke at the Grain Exchange in Milwaukee, in this April 3, 2012, file photo. (AP Photo/M. Spencer Green, File)

Photo by: M. Spencer Green

** FILE ** House Budget Committee Chairman Rep. Paul Ryan, R-Wis. introduces Republican presidential candidate, former Massachusetts Gov. Mitt Romney before Romney spoke at the Grain Exchange in Milwaukee, in this April 3, 2012, file photo. (AP Photo/M. Spencer Green, File)