But labor leaders and Democrats said they would immediately mount a forceful, non-stop campaign to regain control of the Legislature and the governor's office by 2015.
"I'm confident this is in the best interest of Michiganders," Snyder said Tuesday evening, shortly after signing two right-to-work bills approved by the state House of Representatives a short while earlier. The Senate passed the bills last week.
The first bill, establishing a right-to-work law for public-sector unions, passed 58 to 51. The second, applying to private-sector unions, passed 58 to 52.
Democratic State Rep. Jimmy Womack of Detroit wasn't in the House for the first vote, accounting for the one-vote difference between the two bills.
The House immediately sent the bills to Snyder for his signature.
The votes were held as an estimated 12,500 protesters filled the Capitol rotunda and poured out onto the Capitol lawn chanting "shame, shame."
The protesters waved signs, hoisted inflatable rats mocking Snyder and stomped their feet and shouted inside and outside the Capitol building, the Detroit Free Press reported.
After signing the bills, Snyder said, "I don't view this as anti-union at all -- I view this as pro-worker," The Detroit News reported.
Snyder -- a former venture capitalist mentioned in the spring as a possible vice presidential pick for Mitt Romney's failed presidential campaign -- cited the protests as a reason why he signed the landmark legislation in private.
"I don't see the need to have a public signing ceremony to overemphasize that, because this isn't us vs. them," Snyder said while state police troopers in riot gear guarded his office.
The legislation, which Snyder signed almost immediately, goes into effect next year. It bans any requirement that most public- and private-sector employees at unionized workplaces be made to pay dues or other fees to unions.
In the past, those who chose not to be union members were often required to pay fees to unions that bargained contracts for all employees at the workplace.
The legislation does not include police and firefighters, who were intentionally excluded.
Labor leaders predicted a backlash and said they were weighing options in the courts and in future elections.
"The sleeping tiger is awake now," Michigan AFL-CIO President Karla Swift told the Free Press. "We have 2014 as a goal to shift out and win justice."