U.S. Sen. Rob Portman, R-Ohio, left, greets volunteers at a rest stop during Pelotonia Saturday, Aug. 11, 2012, in Columbus, Ohio. Portman called Rep. Paul Ryan "a great choice" Saturday for the Republican running mate spot that Portman was believed to be a top contender for. Portman said he has worked closely with the Wisconsin congressman, and said he is among his best friends in Washington. Republican presidential candidate Mitt Romney introduced Ryan as his vice presidential choice Saturday in Norfolk, Va., ending months of speculation that usually included Portman as among the top possibilities. (AP Photo/Jay LaPrete)