Union supporters swarm the capitol after controversial votes.
The Michigan Senate has passed right-to-work legislation for private sector workers, following earlier approval by the House.
The measure passed on a 22-16 vote Thursday after hours of impassioned debate. Four Republicans joined all 12 Democrats in opposition.
Union activists repeatedly shouted protests from the gallery and cheered Democrats who denounced the measure.
The bill would prohibit unions from collecting fees from nonunion workers, which opponents say would weaken organized labor's ability to bargain for good wages while supporters say it would boost jobs.