Last year, the Post notes, “Tea Party groups complained . . . that they were receiving dozens of questionnaires from the IRS with regard to their applications for nonprofit tax status, probing their political leanings and activities.”

That prompted an editorial from the New York Times cheering on the IRS: “Taxpayers should be encouraged by complaints from Tea Party chapters applying for nonprofit tax status at being asked by the Internal Revenue Service to prove they are ‘social welfare’ organizations and not the political activists they so obviously are.” The Times did say the rules “should be applied across the board,” and the list of groups it wanted investigated included Priorities USA, a pro-Obama group, as well as a couple of conservative groups and Americans Elect, the failed third-party effort.

But the IRS now acknowledges that Tea Party people were right: The agency was investigating them because of their political profile. Viewpoint-based selective enforcement of IRS regulations would be a First Amendment violation even if the regulations themselves are constitutional. It is difficult to credit Lois Lerner’s claim that this was merely an error and not politically motivated. Imagine if the NAACP and the United Negro College Fund got hit with this sort of treatment and the IRS denied a racial motive while acknowledging it had deliberately chosen groups whose names contained synonyms for “black.”