But as county executive, he also clashed with public-sector unions, calling for 35-hour workweeks instead of 40, with corresponding reductions in compensation. He pushed to privatize cleaning and food-service workers. He demanded spending cuts and battled openly with the Board of Supervisors in a county that leaned Democratic. At one point, he went so far as to suggest that the county government itself might be abolished as a way to spare waste.

“It came from eight years of being a county executive,” he said in a recent interview in this southern Wisconsin village. “Nobody needed to tell me what needed to be done. Anytime I had a reasonable option, I’d get shot down by the public-employee union leaders who would rather lay off hundreds of people before they would take even a 35-hour workweek. So I had just grown so frustrated with them throughout the process that I said, ‘Something’s got to change.’ ”

Mr. Walker, the son of a Baptist preacher, was drawn to politics at seemingly every turn. An Eagle Scout, he came of age during the administration of Ronald Reagan, whom Mr. Walker describes as a hero of his.

He lost a hard-fought race for student government president at Marquette University, and eventually withdrew without a degree — an issue that is now drawing extra scrutiny. The last president without a college degree was Harry Truman. Mr. Walker and his wife, Tonette, have two sons in college, and he has said lately that he was thinking about finishing the remaining credits.