The state hasn't voted for a Republican for president since 1984. But Republicans sense opportunity after Walker challenged public sector unions and survived a Democratic push to oust him as governor.
Later today Romney plans to visit Janesville, a town hard hit by the economic recession. He is appearing with Wisconsin Rep. Paul Ryan, the architect of the House Republicans' budget plan.
Romney is in the middle of a five-day bus tour through six states. He also plans two campaign stops in Iowa.