President Donald Trump has vowed to “destroy” the Johnson Amendment, a 1954 provision under which tax-exempt entities like churches and charities cannot participate in any political campaign.

Doing so might actually be cause for concern among the religious organizations pushing for its repeal, a constitutional law expert at Washington University in St. Louis said.

“The immediate motive for the repeal push is clear,” said Greg Magarian, professor of law and expert on law and religion. “A number of politically conservative churches have long complained about the Johnson Amendment. They want the ability to support conservative political candidates openly while retaining their nonprofit status. The Trump administration looks very favorably on that idea.”

When the Supreme Court held in Citizens United v. Federal Election Commission (2010) that corporations may spend freely on behalf of political candidates, many corporations weren’t thrilled, Magarian noted.

“They saw the ruling as removing their protection from political shakedowns —  compromising their autonomy and independence,” he said. “Religious groups rightly prize their independence from government.”

“Likewise, even some skeptics of ‘Big Religion’ laud religious tax exemptions as fortifying the ‘wall of separation’ between church and state. If the government ‘freed’ religious groups to do electoral advocacy, that freedom would bring political pressure to support candidates,” Magarian added. “In considering their positions on the Johnson Amendment, religious groups need to ask whether they care more about their ability to engage in electoral fights or their ability to avoid those fights.”

The broadest problems with repealing or altering the Johnson Amendment would arise if any change included only religious groups, leaving other nonprofits still subject to the amendment.

“Religious freedom concerns might seem to support a surgical excision of religious groups from the amendment’s restrictions,” Magarian said. “However, the Constitution bars religious establishments, and the Supreme Court has sometimes applied that bar to government actions that favor religion in general, as opposed to favoring a particular church, which is plainly unconstitutional.”

In addition, he said, any approach that favored some nonprofits over others for political reasons could violate the Equal Protection Clause.