This past summer, Sen. Bernie Sanders, D-Vt., grilled President Trump's pick for deputy director of the White House Office of Management and Budget over comments he made about Muslims.
In a conservative blog, Russell Vought, an evangelical Christian, defended Wheaton College for forcing out a professor who said Christians and Muslims worship the same God.
"I'm a Christian, and I believe in a Christian set of principles based on my faith," said Vought at his confirmation hearing.
He added, "That post was to defend my alma mater, Wheaton College, a Christian school that has a statement of faith that includes the centrality of Jesus Christ for salvation."
During Vought's confirmation hearing, Sanders asked if the comments were Islamophobic. Sanders ultimately decided he would not vote for Vought.
Religious Beliefs Used as a 'Litmus Test' for Public Office
The attack against Vought shows just how tense the political environment has become for people of faith and the danger of using religion as a litmus test for public office.
"Christians are being discriminated against and this is the hypocrisy of liberalism," said Dallas pastor Robert Jeffress.
"Those who cry the loudest for tolerance are usually the most intolerant people when it comes to ideas with which they disagree," he said.
Following Vought's confirmation hearing, Jeffress demanded that Sanders apologize or resign.
Did Sanders Cross a Constitutional Line?
In an interview with CBN News, he said, "Here we had an evangelical Christian being questioned and Bernie Sanders got into the religious issue and took issue with this nominee's belief that faith in Jesus Christ is the only to heaven. That is the foundation of biblical Christianity for 2,000 years and Senator Sanders started to lecture this nominee and said he wasn't sure he could vote for him."
READ: Franklin Graham Blasts Bernie Sanders for Christophobic 'Religious Test'
Jeffress, a member of the President's Evangelical Advisory Council, said Sanders also crossed a constitutional line.
He explained, "Article Six of the Constitution says government cannot impose a litmus test, a religious litmus test for service. Now you and I can use whatever litmus test we want. But government can't impose that and that's why I said Senator Sanders needs to apologize for what he said or he needs to resign."
The mistreatment didn't end with Vought.
Catholic Nominee Grilled Over Religious Beliefs
In September, Sen. Dianne Feinstein, D-CA, applied her own religious test to federal appeals court nominee Amy Coney Barrett.
Barrett, a law professor at Notre Dame and a practicing Catholic, felt pressured to explain how her religious beliefs might affect her legal decisions.
Feinstein specifically referenced a 2006 graduation speech where Barrett made several references to God.
In her speech, Barrett told graduates, "No matter how exciting any career is, what is it really worth if you don't make it part of a bigger life project to know, love and serve the God who made you."
She went on to encourage students to "pray about your career choices before you make them."
Feinstein said in the confirmation hearing, "When you read your speeches, the conclusion one draws is that the dogma lives loudly within you and that's of concern when you come to big issues that large numbers of people have fought for years."
Metaxas: Religious Tests Are 'Frightening'
Conservative author and radio host Eric Metaxas calls what amounts to a religious test, troubling.
"To me the idea that U.S. senators are this ignorant about this incredibly, utterly central element in American freedom, I find frightening and it should be a wakeup call to everybody," he told CBN News.
He said that acts like this must be called out by all sides.
"Americans should not allow leaders to not understand this," said Metaxas.
"You can have different views of faith or whatever but when you don't understand that that is sacrosanct. In America for 240 years we have said you never go there. That is pure bigotry."
While liberals might consider their actions as just political posturing, Metaxas sees the problem as much more serious.
"When Sen. Feinstein did this recently, I thought, she actually thinks that what she's saying is okay. She thinks it's just politics. It's not just politics. It's fundamentally unconstitutional," he said.
Meanwhile, Jeffress believes the problem is likely to get worse.
"I don't believe that is the call for fatalism and I see that in too many Christians," he said.
"They just throw up their hands. It's all going to go to hell in hand basket, let's just get in our holy huddles and try to encourage one another and hope nobody does anything bad to us. That is not what Christians need to be doing. We are to be on the offense," said Jeffress.
Metaxas says the best way to do that is through prayer.
"The one thing however that we have as Christians is we have the power of prayer and we need to pray against this."
He added, "This is not God's will. It's God's will that everyone be genuinely free and we need to pray hard that in this nation that this would be preserved," he said.