Senate Majority Floor Leader Arlan Meekhof said a number of factors influenced the decision to push ahead, including Snyder's endorsement and the ballot initiative, which put right-to-work in the spotlight. Primarily, however, Republicans recognized they had enough votes to capture a long-sought prize, he said.
"I wouldn't say there was a sense of urgency, but a sense of opportunity," Meekhof said.
Democrats contended Republicans, who lost five House seats in the November election, wanted to act before a new legislature takes office next month. In passionate floor speeches, they accused the majority of ignoring the message from voters and bowing to right-wing interest groups.
"These guys have lied to us all along the way," Senate Democratic leader Gretchen Whitmer said. "They are pushing through the most divisive legislation they could come up with in the dark of night, at the end of a lame-duck session and then they're going to hightail it out of town. It's cowardly."
Eight protesters were arrested for resisting and obstructing, state police Inspector Gene Adamczyk said. At one point, officers barred entry to the Capitol as a safety measure, saying the building was overcrowded. It was reopened after unions successfully petitioned Ingham County Circuit Judge Joyce Draganchuk for an order overturning the move.
In the end, the bills sailed through — even though some Republicans were opposed. The Senate approved a measure dealing with private-sector workers 22-16. As Democrats stormed out of the chamber, a second bill applying to government employees was passed, 22-4.
The House approved a private-sector employee bill 58-52. Both chambers are expected to approve two identical measures next week. Leaders said they would include exemptions for police and firefighters, who are covered by existing law requiring binding arbitration for their labor disputes.
A $1 million appropriation was tacked onto the bills for what a House spokesman described as implementation and worker education activities. Spending bills are legally protected from being overturned by statewide referendums.
United Auto Workers President Bob King, who joined the protesting crowd, said the bills' passage was "a very partisan, polarizing attack."
A White House spokesman said President Barack Obama continues to oppose right-to-work laws.
"Michigan — and its workers' role in the revival of the U.S. automobile industry — is a prime example of how unions have helped build a strong middle class and a strong American economy," the spokesman said.