Meanwhile, Fox News contributor Steven Crowder was punched repeatedly in an altercation with one protester.
Schauer served one term; he beat Rep. Tim Walberg (R) in 2008 only to lose to the former congressman two years later.
Tear gas was sprayed at least once, according to the Detroit Free Press. At least two people were arrested for trying to force their way into the George W. Romney building, where Gov. Rick Snyder (R) has an office. The governor has pledged to sign the contentious legislation, a final version of which passed the state House on Wednesday.
Tensions flared earlier in the day as pro-union protesters appear to have torn down a tent maintained by Americans for Prosperity, a group backed by the billionaire Koch brothers that was rallying in support of "right to work."
"They couldn't engage in a civil debate, and it's very unfortunate," Scott Hagerstrom, executive director of AFP-Michigan, told the Detroit News.
Crowder, a conservative comedian, was interviewing protesters nearby when he was confronted by one man and punched repeatedly. He has posted video of the incident and photos of his injuries.
Update: The Fox News contributor has filed a complaint with the Michigan police. It's not clear how the fight started; Crowder says he pushed some people that were trying to take down the tent.
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