The list of labor unions backing Hillary Clinton’s presidential campaign is getting hefty. The American Federation of Teachers (AFT) pledged its allegiance in July. The National Education Association (NEA) followed suit in early October. Next up was the American Federation of State, County, and Municipal Employees (AFSCME), which endorsed Clinton last week.

Big Labor’s inseparable alliance with the Democratic Party is made anew every election cycle, but it still begs the question: Do union members feel the same way?

The answer is no. Exit polls from 2012 and 2014 show that about 40 percent of union households vote Republican, even though roughly 90 percent of union dollars go to Democrats and left-wing causes—and, it seems, 100 percent of union endorsements. This reveals a gaping disconnect between union leadership and rank-and-file union members, who are far more diverse in their political views than their “representatives.”

The Employee Rights Act (ERA) would narrow the gap by guaranteeing union members the right to refrain from sending dues money to political candidates and causes they don’t support. In doing so, the bill would require union bosses to obtain opt-in permission before sending member dues off to Democrats and left-wing causes.

Union bosses have a duty to serve their members, not just the Democratic Party. The ERA would ensure that they fulfill it.