Republican presidential candidate and Wisconsin Governor Scott Walker takes a selfie with supporters during a visit at a Harley Davidson motorcycle dealership in Las Vegas, Nevada July 14, 2015. Walker jumped into the race for the 2016 Republican presidential nomination on Monday, needing to prove he has learned from early missteps and can appeal to voters beyond the conservatives who dominate the first nominating contest in Iowa. REUTERS/David Becker TPX IMAGES OF THE DAY