FILE - In this March 16, 2013 file photo, Wisconsin Gov. Scott Walker arrives to speak in National Harbor, Md. Republicans governors running for re-election next year are looking to capitalize on distaste for Washington, D.C., gridlock and President Barack Obama’s dropping public approval amid the pitfalls of rolling out his signature health care law, and Democratic challengers may need to respond with a popular cause. A minimum wage increase could be the answer. (AP Photo/Carolyn Kaster, File)