John Koskinen, the new IRS commissioner, is on the hot seat and would do well to follow the example of Johnnie Mac Walters, who held the same post when President Nixon occupied the Oval Office. After Nixon aide John Dean handed Walters an envelope with a list of some 200 individuals the president considered political enemies, Walters refused to go along with the request for audits. He locked the list in his safe without ever opening the envelope. He subsequently gave the envelope to the congressional Joint Committee on Taxation. Considering Nixon's paranoid penchant for revenge, Walters' decision to defy him was not without risk.

Nixon wasn't the first president to try to use the federal tax agency as a political weapon, and President Obama surely won't be the last chief executive to do so. That is why what Koskinen does in coming months is crucial to restoring the agency's credibility as an uncompromisingly nonpartisan arm of the federal government. There is little doubt about what Walters would suggest, since he told the Greenville (S.C.) News in May that he was "distressed at what's happening and particularly with IRS. The IRS must be run nonpolitical. Our tax system otherwise will fail and we can't afford that."

To that end, Koskinen should start the IRS cleanup by withdrawing new regulations designed to bring “clarity” to the agency's tax exemption enforcement. In fact, these rules are a transparently political attempt to legitimize the president's suppression of conservative, evangelical and Tea Party critics. As House Ways and Means Committee Chairman Dave Camp said Friday:

“Before having all the facts in hand, [the] Treasury [Department, the IRS' parent agency] rushed forward with new rules that seriously limit groups' ability to engage in public debate. It is clear that the Obama Administration is still targeting conservative groups and wrote these rules to put them out of business. This is pure politics, and the new IRS commissioner should do the right thing and put a stop to it.”

Under the IRS proposal, nonprofits would risk their tax-exempt status if they sponsored voter registration, get-out-the-vote efforts or candidate forums. Such activities are intrinsic to the democratic process, contribute positively to public understanding of the issues and candidates when done in a nonpartisan fashion, and have been sponsored routinely for decades by nonprofits across the ideological spectrum. These also happen to be the same sort of activities that would be conducted by the more than 200 conservative, Tea Party and evangelical nonprofit applicants that were targeted for harassment by Obama's IRS.

Camp has introduced the Stop Targeting of Political Beliefs by the IRS Act of 2014 to put a one-year hold on the proposed rules, pending completion of the congressional investigation of the IRS targeting scandal. Senate Minority Leader Mitch McConnell, R-Ky., has introduced a companion measure in the Senate, but Senate Majority Leader Harry Reid, D-Nev., will prevent any Senate action on the measure. Even so, Camp should spare no efforts to gain passage in the House.