Jillian Kay Melchior highlights for National Review Online readers an interesting new study about the political impact of labor union dues.

An exhaustive new study from the Center for Union Facts (CUF) crunched the numbers on union political spending, tracking down where members’ dues ended up. Nearly $140 million — about 99 percent of all union political contributions — went to Democrats and liberal causes, the study found.

But a sizeable minority of union members nationwide lean right, preferring Republican candidates and conservative causes. One recent Gallup poll found that around one in four members of private- and public-sector unions identified as Republican. A study by Cornell’s Roper Center found that 40 percent of union households voted for Mitt Romney in 2012. Numerous exit polls in recent years have found that between 35 and 40 percent of union households vote Republican.

“I believe what this illustrates is that union members have very little control over their own dues money, which is supposed to be for collective bargaining — but a whole lot of it is going to political causes and political advocacy,” says Richard Berman, executive director of CUF.

Planned Parenthood and its advocacy nonprofit received $435,000 in 2014 from unions spending their members’ dues. Most of it came from the American Federation of State, County, and Municipal Employees, CUF says.

In 2014, major unions also gave more than $680,000 to Al Sharpton’s tax-indebted nonprofit, the National Action Network, and more than $108,000 to Jesse Jackson’s Rainbow/PUSH Coalition.