Things to know about Wisconsin Governor Scott Walker

He becomes the 15th Republican candidate for 2016

(Getty Images/Win McNamee)

Wisconsin Governor Scott Walker will announce his bid for the 2016 presidential campaign on Monday.

1. He's the subject of a state criminal investigation into illegally coordinating campaign funding.

The US Supreme Court has put a hold on whether a conservative group illegally coordinated with Mr Walker's 2012 recall campaign.

2. He’s notorious for breaking up unions.

Mr Walker rose to prominence by ending collective bargaining for public workers.

Josh Goldstein, president of the American Federation of Labor and Congress of Industrial Organizations, issued a one-sentence reaction to the Governor's Monday announcement.

“Scott Walker is a national disgrace.”

3. He didn’t finish college.

Mr Walker enrolled at Marquette University in 1986. During his junior year he was offered a job at the American Red Cross and he left school to pursue his professional career.

4. He’s been backed by the Koch Brothers.

David and Charles Koch told donors in April that they supported Mr Walker's campaign and that he should be the Republican nominee, the New York Times reported.

The Koch Brothers are big spending, highly influential Republican donors who have pledged to spend nearly $900,000 advancing conservative politics over the next two years.

5. And he once worked at a McDonald’s.