Scott Walker was elected governor of Wisconsin in 2010.
He faced state voters again in 2012 after Democrats and organized labor secured enough signatures to force a recall election following Walker's controversial plan to strip most public workers of union rights.
Walker survived the recall election.
http://www.usatoday.com/story/news/politics/2013/11/26/scott-walker-2016-president-republican-nomination/2070417/