This op-ed column was originally published at WashingtonExaminer.com

Rick Berman, CUF Executive Director

With the presidential primaries right around the corner, we’re hearing a lot about “dark money” in politics — that is, political spending from deep-pocketed, undisclosed sources. Democrats claim it’s corrupting the political system and helping Republicans to boot. But they’re happy to play ball if it benefits approved left-wing causes.

Hillary Clinton ally David Brock has used his Media Matters vehicle to attack conservative advocacy groups for keeping their donors private. Other than Brock’s hypocrisy — his group doesn’t disclose its own donors — there’s really nothing nefarious about Americans privately supporting charities and causes that they believe in.

But Brock isn’t the only donor-disclosure hypocrite on the Left. Union bosses, the Left’s personal ATM for years now, have long spoken out against secret spending. In the run-up to the 2014 election, AFL-CIO President Richard Trumka released the following statement: “[D]ark money has flooded our elections and made our American politics even less fair for working people.” American Federation of Teachers President Randi Weingarten echoed that sentiment in a recent tweet, “The unlimited flow of secret money into elections threatens our democracy.”

Yet labor unions send tens of millions of dollars to liberal advocacy groups closely aligned with the Democratic Party each year — many of which aren’t required by law to disclose their donors and choose not to. A recent analysis by the Center for Union Facts found that Big Labor sent almost $140 million to this left-wing machine in 2014, or 99 percent of its political advocacy expenditures.

David Brock himself was a big beneficiary: His various entities, including super PAC American Bridge 21st Century and Media Matters, received $455,000. Democratic operative Brad Woodhouse, a longtime friend of Brock’s who officially files election complaints on behalf of another Brock-linked group, was even more fortunate: One of his advocacy groups, Americans United for Change, raked in almost $1.8 million last year.

Does Woodhouse’s group disclose its donors? No.

Weingarten — who rails against “secret money” in politics — also supported AUC with two separate $50,000 checks from her union in 2014 and a $90,000 donation just this year (Trumka’s AFL-CIO chipped in with $40,000).

(It should be noted that Woodhouse has gone on record comparing Republicans to “the Taliban and Hamas” and calling critics of President Obama “treasonous.”)

But the real victim of union political advocacy spending is not the Republican Party; it’s individual union members who are forced to support Mr. Woodhouse’s outbursts without ever signing on. Exit polls from 2014 indicate that about 40 percent of union households vote Republican, yet 99 percent of political advocacy spending went to Democrat-aligned groups.

And while union PAC spending allows union employees to either sign on or not, the same option is not available for tens of millions of dollars in advocacy spending—that money comes directly from member dues.

If Democrats cared about campaign finance reform, they would acknowledge this shocking gap in democracy. And they might support the Employee Rights Act, a popular piece of legislation that allows union employees to preemptively decide where their member dues are going — rather than run the maze to get a refund.

It wouldn’t prohibit Big Labor from financing David Brock’s secretive network, but the ERA would give employees a fair chance to say yes or no. The substantial minority of union members voting Republican would certainly appreciate that option.

Democrats can complain all they want about “dark money,” but they shouldn’t be simultaneously sticking their hands out for it.