Republican vice presidential nominee, Rep. Paul Ryan of Wisconsin walks across the stage with sons Sam, left, Charlie, right, and daughter Liza during a podium sound check at the Republican National Convention in Tampa, Fla., on Wednesday, Aug. 29, 2012. (AP Photo/Charles Dharapak)

Photo by: Charles Dharapak

Republican vice presidential nominee, Rep. Paul Ryan of Wisconsin walks across the stage with sons Sam, left, Charlie, right, and daughter Liza during a podium sound check at the Republican National Convention in Tampa, Fla., on Wednesday, Aug. 29, 2012. (AP Photo/Charles Dharapak)