First of all: We should all be celebrating that last night voters in Missouri rejected a right-to-work law by a 2-to-1 margin.

Why? The average person in the United States has essentially zero power in society. That’s why millions have organized into unions over the years. But the slow decline of unionism in the United States should concern you even if you’re not in one.

Unions improve wages, benefits and working conditions for their members. But it’s not just to members’ advantage. Collective bargaining affects pay standards across entire industries, meaning even nonunion workers benefit. Unions also secure legislation that protects all workers, from workplace safety guidelines to a guaranteed weekend. And they reduce gender and racial wage gaps across industries, which contributes to broader equality in society.

Owing largely to a sustained political assault on unions, their memberships have been declining since the mid-20th century — a trend that, not coincidentally, maps neatly onto rising economic inequality and falling wages. The Supreme Court’s recent decision in Janus v. American Federation of State, County and Municipal Employees is the latest blow to unions, effectively instituting a nationwide “right-to-work” regime for public-sector unions. Right to work forces unions to represent even those who don’t pay dues or claim membership, discouraging workers from joining and contributing. In short, it kills unions by attrition.