Scott Walker, governor of Wisconsin and 2016 Republican presidential candidate, center, pauses while speaking with the media during the Iowa State Fair in Des Moines, Iowa, U.S., on Monday, Aug. 17, 2015. Like most every other candidate in the historically crowded field, the Wisconsin governor's standing in state and national polls has been hurt by the summer surge of billionaire Donald Trump, the party's front-runner. Photographer: Daniel Acker/Bloomberg via Getty Images
Getty Images

Bloomberg Bloomberg