Then-Senator Barack Obama at an AFL-CIO Conference in 2005. (Photo: Chip Somodevilla/Getty Images)

Then-Senator Barack Obama at an AFL-CIO Conference in 2005. (Photo: Chip Somodevilla/Getty Images)

Donors like the Koch brothers make the news a lot, but did you know unions are five of the top 10 groups giving political donations so far in the 2014 election cycle?

Among these five, more than $19.3 million in members’ dues has flowed to candidates, political parties and outside political groups.

When it comes to candidates and political parties, the National Education Association has given 89 percent to Democrats. The American Federation of State, County and Municipal Employees (AFSCME) has given 100 percent to Democrats. The AFL-CIO has given 81 percent to Democrats, and the International Brotherhood of Electrical Workers has given 97 percent to Democrats.

Of course, Americans are free to give to candidates and causes they support. But for unionized workers, dues come out of their paychecks and go to political causes—and they aren’t consulted on where that money will go.

In the 2012 election cycle, a surprising report revealed that “Organized labor spends about four times as much on politics and lobbying as generally thought.”

Heritage labor expert James Sherk says that this system stays in place only because unions have power over their dues-paying members.

Polls show that the vast majority of union members think their union spends too much on politics and that they don’t like their union’s political priorities. It isn’t hard to see why, with such enormous spending and virtually all of it going to one side of the political spectrum. This wouldn’t happen if unions had to get their members’ permission before spending their dues on political campaigns.

Read more about the ways unions are trying to coerce new members