Long before the Internal Revenue Service revealed it had improperly targeted conservative 501(c)(4) groups, a group of Democratic senators led by New York Sen. Chuck Schumer urged the IRS to do just that.

The IRS’s admission last Friday that it had singled out tea party and other groups for extra audits and delays has raised concerns that President Barack Obama’s administration quietly attempted to stymy opponents through intimidation. But many prominent Democrats — including Montana Sen. Max Baucus, Americans United for the Separation of Church and State and the New York Times editorial board — had been publicly calling for tighter restrictions on 501(c)(4) groups affiliated with the tea party and conservatives.

Last year, Schumer, along with Democratic Sens. Michael Bennet, Sheldon Whitehouse, Jeff Merkley, Tom Udall, Jeanne Shaheen and Al Franken, penned a letter calling on the agency to cap the amount of the political spending by groups masquerading as “social welfare organizations.”

A press release from Schumer’s office dated March 12, 2012 laid out the terms of the letter:

The senators said the lack of clarity in the IRS rules has allowed political groups to improperly claim 501(c)4 status and may even be allowing donors to these groups to wrongly claim tax deductions for their contributions. The senators promised legislation if the IRS failed to act to fix these problems. “We urge the IRS to take these steps immediately to prevent abuse of the tax code by political groups focused on federal election activities. But if the IRS is unable to issue administrative guidance in this area then we plan to introduce legislation to accomplish these important changes,” the senators wrote.

The letter cited a March 7, 2012 New York Times article by Jonathan Weisman that suggested donations to groups like American Crossroads and Priorities USA could be tax deductible, which was a primary concern of those senators at the time.

A number of those senators participated in a press conference about their efforts on March 21, 2012, and Franken spoke out about what he called lack of oversight of 501(c)(4) status.

“I think that there hasn’t been enforcement by the FEC and the IRS, and so there are entities that are taking a 501(c)4 status, and under that they’re supposed to have more than half of their activity be non-political,” Franken said. “That’s pretty hinky. I mean, they really aren’t doing that, and that I think there needs to be a look at that — that even under the laws that already exist, there are people who should be disclosing who aren’t. And I think that is where we’re seeing the effect of — lack of effective enforcement and just oversight.”

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