Since 2008, a group of predominantly conservative, Protestant churches have participated in Pulpit Freedom Sunday—a day started by the conservative legal group Alliance Defending Freedom, when hundreds of pastors across the country give explicitly political sermons in protest of the IRS’s rule. The movement has been growing, and religious leaders will often mail tapes of their sermons directly to the agency to showcase their defiance.

The IRS doesn’t often go after these churches, though. Agency leaders have emphasized the importance of educating religious organizations about what is and is not legal, rather than aggressively initiating audits or trying to revoke the non-profit status of houses of worship. The agency has rarely pursued this last option; one of the most prominent recent cases was in 1995, when it denied the non-profit status of an upstate New York church that took out a full-page ad in USA Today warning Christians not to vote for Bill Clinton in 1992.

In general, though, “the political climate has changed in the last four or five years, where attacks on the IRS has been more frequent, more virulent, and the IRS has become extremely defensive,” Galston said. Especially with the budget cuts of the last half decade, the agency has scarce resources for enforcement of the Internal Revenue Code. “They can’t, in my view, allocate the resources in such a way that they preclude proper enforcement of the other code sections,” Galston added.

Yet even beyond purposeful protests like Pulpit Freedom Sunday, religious leaders seem to openly defy the ban on participating in political activities. The televangelist Mark Burns has openly stumped for Trump, as has Liberty University president Jerry Falwell Jr. And at the start of the Democratic National Convention, the Decatur, Georgia, pastor Cynthia Hale prayed for Hillary Clinton to become president. Even if the IRS would not see these actions as formal violations of the law, the difference between pastors electioneering and speaking as private citizens “is a fine distinction that is easily evaded,” said Galston.

Critics of the agency, including some progressive religious groups, argue that the IRS should put more resources toward enforcing the electioneering ban. The main question, said Alan Brownstein, a law professor at the University of California, Davis, is not whether religious groups and leaders should be able to express their views—it’s whether that activity should be subsidized by the government. “Pastors can say whatever they want, as can anyone else,” he said. “The question is whether a tax-exempt institution can say whatever it wants and retain its tax-exempt status, and whether the pastor as an official can use his or her position in the tax-exempt institution to engage in electioneering.”

Although religious groups often participate in political and campaign activities in defiance of the law, only Congress could make these activities fully legal. And doing so would raise big questions about money: Would religious organizations get to keep their tax-exempt status if they were permitted to participate in campaigns and endorse candidates? More importantly, could people still make tax-deductible donations to religious organizations—effectively giving money to promote a particular candidate or campaign?