The Internal Revenue Service Building in Washington. (Andrew Harnik/AP)

TO GET something changed in Washington, take the front door: propose a law and get it passed by Congress and signed by the president. Or, take the side doors and back doors through the vast regulatory machinery and executive-branch agencies. All kinds of political forces and special interests have exploited this over the years. Now comes a new example: Conservatives who long sought to restrain the Internal Revenue Service have managed to throw a wrench into an IRS division that is supposed to regulate tax-exempt nonprofits and charities, just at a time when these groups are becoming more partisan and complex.

In a Dec. 18 article in The Post, reporter Robert O’Harrow Jr. offered a disturbing picture of the besieged Exempt Organizations division of the IRS, which regulates charities and nonprofits such as those allowed under sections 501(c)(3) and 501(c)(4) of the tax code. The former may not directly or indirectly support a political candidate, but they are allowed to participate in educational debates about the issues; the latter are social-welfare groups that can be involved in politics only so long as it is not their primary activity. The number of applications from new charities has exploded in recent years, and the law is a bit of a gray zone — vaguely written and hard to enforce.

In recent years, overwhelmed by applications, the division and its then-leader, Lois Lerner, fell into the crosshairs of the conservative tea party movement for the slow pace of approvals of tea party groups, which they claimed was due to a conspiracy by the Obama administration to target them. Subsequent investigations found mismanagement — the IRS was taking shortcuts and using keywords to deal with the mountain of applications — but not deliberate targeting.

Still, the charges took a toll. The division seems to have lost its will to scrutinize charities. According to Mr. O’Harrow, last year the division rejected just 37 of the 79,582 applications on which it made a final determination. He reported that charities have now begun to recognize they face little or no chance of examination or sanction. The division’s budget has declined from a peak of $102 million in 2011 to $82 million last year. The number of division employees has fallen from 889 to 642. The IRS created an expedited application for small charities that required no supporting documentation; a subsequent study found that more than a third of the approved groups that used it were not qualified and should not have been approved.

There is more than enough blame to go around in this tale. The conservative groups, their allies in Congress and the IRS itself all bear responsibility. It is clear what the result will be. Voters will have less and less knowledge of who is paying for political activity in their democracy, even as many politicians hypocritically claim to favor transparency.