Mr. Wallace asked Mr. Durbin why he singled out Crossroads GPS for an IRS investigation and pointed out that his letter “did not mention one single liberal group.” Mr. Durbin offered this ludicrous defense: If the IRS investigated GPS, “every other group would be put on notice.” Correction: An IRS investigation of a conservative 501(c)(4) would leave liberal 501(c)(4) groups gleeful—especially since liberal groups have operated for decades in the same way GPS does without Democrats complaining.

Democrats were content to have 501(c)(4) groups active as long as they were operating on behalf of liberals and their causes. For example, no Democratic leader demanded the IRS investigate the 501(c)(4) arms of the League of Conservation Voters, National Abortion Rights Act League, VoteVets, NAACP, Defenders of Wildlife, Sierra Club and other liberal organizations that have spent millions excoriating Republicans, pushing liberal issues and registering voters. …

In addition, no Democratic leaders decried big money’s influence when groups registered under section 501(c)(5) of the federal code—the tax exemption for labor, agricultural or horticultural organizations—spent hundreds of millions from corporate treasuries on advocacy and political activity. That’s because Democrats believe unions are more deserving of tax-exempt status than other organizations, and that corporate contributions are bad unless they come from unions’ corporate treasuries.