Amid Rep. Beto O’Rourke’s (D-Texas) challenge to remove tax-exempt status for churches that are not supportive of same-sex marriage, Sen. Thom Tillis (R-N.C.) in an opinion piece on Fox News explored how religious freedom in the United States is being greatly threatened.

As a member of the Senate Armed Services Committee, a Veteran Affairs Committee, and a Fox News contributor, Tillis cited Pastor Andrew Brunson’s words to discuss the “uncertain future of religious freedom here in America.”

“These are values that need to be carefully guarded,” Tillis explained using Brunson’s words. “They are not innate to man’s nature. They’ve been built carefully over the years and developed over the years. It’s a culture and culture is taught. It’s passed on from one generation to another. So if one generation refuses that culture or doesn’t teach it or pass it on, then you can lose that within a generation. And I think we’re very close to that.”

O’Rourke sparked greater controversy than ever when last week he promised, if elected president, to strip churches of tax-exempt status if they do not support same-sex marriage, according to Fox News.

When asked by CNN anchor Don Lemon last week if religious institutions—including colleges, churches and charities—should have tax-exempt status removed, O’Rourke responded “Yes” without hesitation.

Tillis in his article provided an explanation based on the Bill of Rights, where the Founding Fathers incorporated an Establishment Clause to “ensure the separation of church and state” to prevent “future demagogues in government from endorsing a state religion or providing favoritism to some religious sects over others.”

Tillis said O’Rourke’s radical proposal was “a chilling attempt to subvert the constitutional rights of Americans of faith in order to socially engineer our places of worship,” and that the rights of conservative students on college campuses are being restricted under the radical proposals of Democratic presidential candidates.

Tillis also noted that the “extreme positions” embraced by Democrats are used to “appease their fringe left-wing base,” and that Democrats are “already supportive of punishing private small business owners” based on their religious practices, should these religious views stray from their view of the world.

In closing, Tillis warned of the intimidation and pressure from Democrats whose path will be “through the courts by confirming left-wing judges who will legislate from the bench,” even if they “may not be so bold as to push for legislation” that completely eliminates religious institutions or deprives Americans of their religious freedoms.

“The effort to undermine those [religious rights] is already well underway, representing an existential threat to the values that make America a great and tolerant nation. We must be prepared to defend our religious freedoms through the courts and at the ballot box,” he said.

President Donald Trump, at an American Airlines Arena rally in Dallas, branded O’Rourke as a “very dumb Democrat” for his desire to revoke the tax-exempt status of “many churches and religious charities.”

“Beto, in a few short weeks, got rid of guns then got rid of religion,” the president added, blasting O’Rourke for wanting to boycott guns and restrict religious liberty. “Those are not two good things in Texas to get rid of.”