When Republicans unveiled tax reform legislation on Thursday, discussion surrounding the bill centered on its potential impact on middle-class households and its apparent giveaway to the economic elite.

But another proposed change ― featured way down on pages 427 and 428 of the 429-page draft bill ― is raising a red flag for advocates of the separation of church and state.

The legislation proposes changes to the Johnson Amendment, a 63-year-old tax law that prohibits churches and other tax-exempt organizations from participating in political campaigns. Under the Republicans’ proposed bill, members of the clergy who endorse candidates from the pulpit would be legally protected.

Religious organizations would not risk losing their tax-exempt status “solely because of the content of any homily, sermon, teaching, dialectic, or other presentation made during religious services or gatherings,” the bill specifies, according to The Washington Post.

The stipulation doesn’t “get rid of and totally destroy the Johnson Amendment,” as President Donald Trump vowed to do shortly after his inauguration. It applies only to religious institutions and not to other tax-exempt nonprofits. And clergy would be able to endorse candidates and policies in sermons but still would not be permitted to make financial contributions to campaigns on behalf of their churches.

Only Congress has the power to officially repeal the amendment. Doing so could allow individuals to make tax-exempt political donations by way of churches ― something advocates say might undermine the integrity of the tax system and transparency in political campaigns.

Still, the proposed changes constitute a substantial departure from a tax policy that many secular advocates believe to be fundamental to the separation of church and state.

Larry T. Decker, executive director of the Secular Coalition for America, said in a statement: “Religious nonprofits are already exempt from taxes and financial transparency. The repeal of the Johnson Amendment would bestow churches with unprecedented power and exempt them from all accountability to the taxpayers and the parishioners who fill their coffers.”

Maggie Garrett, legislative director of Americans United for the Separation of Church and State, also warned that the legislation could leave religious leaders and institutions vulnerable to pressure from politicians looking for endorsements.

“This is bad policy,” Garrett said in a statement. “It’s bad for churches, and it’s bad for American taxpayers who will potentially see their money going to support partisan political operations being run out of church basements.”

Amanda Tyler, executive director of the Baptist Joint Committee for Religious Liberty, said: “Pastors and people of faith know that there’s nothing free about a pulpit that is bought and paid for by political campaign donations or beholden to partisan interests.”

Tyler also noted that a majority of Americans are opposed to such political endorsements by religious leaders.

A Pew Research Center survey from 2016 found that though many Americans agreed that churches and other houses of worship should express their views on social and political matters (47 percent), a strong majority didn’t think churches should endorse specific political candidates (66 percent).