Hundreds of millions of dollars have been spent using undisclosed front groups to influence political campaigns and elections. This trend has been aggravated by the Citizens United Supreme Court decision, with many corporations preferring undisclosed nonprofits as the vehicle to deliver hard-hitting, and often deceptive, television advertisements against lawmakers. But a simple measure to allow the public to know who is buying these advertisements keeps getting filibustered in the U.S. Senate.

On Monday, the Senate plans to vote on whether to even debate the DISCLOSE Act, a bill that would in no way limit campaign expenditures, but simply allow transparency in advertising.

Two days ago, we ran into Senator Mike Enzi (R-WY), who we found outside his office building making fundraising calls for Connie Mack on his cell phone. We asked Enzi if some form of disclosure legislation deserves an up or down vote, given the phenomenon of “dark money” in the election.

Enzi furrowed his brow and asked if we were a “Republican blog.” “Republic Report is our blog,” I corrected him. He then mumbled, “I don’t know” to our question about disclosure and walked off. (See video above).

Not too long ago, Republicans — even Mitch McConnell — supported campaign disclosure.

“Anything that moves us back towards that notion of transparency and real-time reporting of donations and contributions I think would be a helpful move towards restoring confidence of voters,” said Eric Cantor in January of 2010. Months later, Cantor voted against a bill to do just that.

Proponents of the DISCLOSE Act, which would allow voters to see the top donors to a group at the end of a campaign advertisement and require undisclosed nonprofits to conform to the same transparency standards applied to PACs and Super PACS, have posted a list of over a dozen prominent GOP lawmakers who have gone on record supporting sunlight in campaigns. Unfortunately, every single member on the list, like Cantor, has changed their position and now supports secrecy. Even John McCain, who relied on anonymously-funded lobbying groups to win a contentious primary in 2010, has backed away from disclosure, a cause he once championed.

Lobbyists have leaned on both parties, but particularly the Republicans, to block any effort to add transparency to the system. The U.S. Chamber of Commerce, which is funded mostly by multinational corporations, has led efforts in support of secrecy.

But not all Republicans have shunned disclosure. Congresswoman Anna Eshoo (D-CA) offered an amendment mirroring the provisions of the DISCLOSE Act in March, which provided a chance for the full House of Representatives to vote on the bill. Five Republicans, including Reps. Todd Platts (R-PA) and Walter Jones (R-NC), voted in support of the amendment.

The DISCLOSE Act passed the House and was filibustered by a minority of Republicans in the Senate in 2010. This year, with members like Enzi more focused on raising cash for the election than cleaning up campaigns, it looks like it won’t even get debate in either chamber.