These reforms didn't stay voluntary for long. The Wagner Act codified collective bargaining as a right and forced employers to negotiate with unions. Union membership jumped from 7% to 34%. Politically speaking, this was a game changer. To this day, despite much more lukewarm support from the Democratic Party, labor unions remain a fairly loyal voter base for that party. This was a pro-worker move but it was also a pro-party move to shore up a loyal bloc of voters.