FILE - In this April 2, 2012 file photo, Republican presidential candidate, former Massachusetts Gov. Mitt Romney listens at left as House Budget Committee Chairman Rep. Paul Ryan, R-Wis., speaks in Milwaukee. There are plenty of reasons for Republican presidential candidate Mitt Romney to choose Wisconsin Rep. Paul Ryan as a running mate. The whip-smart congressman is from a battleground state. He?s the GOP?s leading voice on the nation?s budget and is the rare member of the Republican establishment who?s loved by the tea party. (AP Photo/Steven Senne, File)