Missouri voters soundly rejected the state's right-to-work law on Tuesday, meaning a huge win for labor unions.
Last year, the state's Republican-led Legislature passed a right-to-work law, which would have made it illegal to force workers to pay union dues as a condition of employment. Opponents forced a suspension of the legislation by gathering more than 300,000 signatures to put the law to a vote by the people.
Known as Proposition A, the bid to make Missouri a right-to-work state, was overwhelmingly defeated by referendum in Tuesday's primary election. More than 67 percent of voters rejected the measure, according to the secretary of state.
Missouri is the first state to overturn a right-to-work law by referendum, Fortune reported.
AFL-CIO President Richard Trumka hailed the victory, telling the Wall Street Journal, "We're just getting started. We'll build on this tremendous achievement in the days and weeks to come."
Unions were dealt a blow in June when the United States Supreme Court ruled 5-4 that government employees cannot be forced to pay union dues. Missouri's referendum was the first battle following that decision, and the labor movement poured immense resources into the state to see Proposition A defeated.
Outspending proponents of right-to-work by nearly 5 to 1 ahead of the vote, union groups knocked on more than 500,000 doors while making their case to Missourians.
The group Missourians for Freedom to Work had campaigned for passage of the right-to-work law, but treasurer Greg Hoberock told CNN he thought the labor movement nationally was fighting to protect its own "way of life."
"From the unions' perspective, they view this as a battleground state," he added.
Prop A was supported by the Missouri Chamber of Commerce. The group's president, Dan Mehan told the Journal following defeat, "We got outspent. We're disappointed obviously, but it doesn't take away from the benefits of being a right-to-work state."
According to the National Right to Work Committee, right-to-work states have a higher standard of living, lower unemployment numbers, and faster growth in manufacturing and nonagricultural jobs. The group says that over the past 30 years, union income has more than doubled in inflation-adjusted dollars.