President Donald Trump stood in front of a microphone Thursday, gloating about his impeachment trial acquittal and showering his biggest advocates with praise. After entering the White House East Room to the tune of “Hail to the Chief,” he called Sen. Chuck Grassley (R-Iowa) an “incredible guy,” told Sen. Mike Braun (R-Ind.) he did a “great job” and led a standing ovation for Senate Majority Leader Mitch McConnell (R-Ky.).

Trump had good reason to dole out the back slaps. Since he was charged in December with pressuring Ukraine to help sabotage his political rivals and blocking the House’s attempt to investigate the issue, Republican senators have rallied around him like a fortress wall.

They blocked witnesses from testifying at the Senate trial and used lies, conspiracy theories and acrobatic logic to try to prove his innocence. Sen. Mitt Romney (R-Utah), the only Republican in the Senate to vote for Trump’s removal from office, has been skewered by the president and some members of the GOP over the past few days. On Friday, Trump dismissed two House impeachment witnesses, saying he was “not happy” with them.

And though this behavior might seem like dirty politics as usual, psychologists and professors say the extreme measures Republicans took to defend Trump resemble a more sinister phenomenon: the mentality of cult members.

“They’ve just refused to entertain any ideas that go against their leader,” said Janja Lalich, a sociology professor at California State University, Chico, who studies cults and extremist groups. “That kind of closed-mindedness is just so typical of cult members.”

Many experts and politicians have made the comparison between Trumpism and cults. Lev Parnas, an associate of Trump’s personal lawyer Rudy Giuliani, said there was a “cult-like” atmosphere around the president, as did Anthony Scaramucci, Trump’s former communications director. Joe Walsh, the former Illinois congressman who launched a failed bid to challenge Trump’s nomination, said point-blank: “My Republican Party isn’t a party. It’s a cult.”

Though some professors who study groups think this description is overly simplistic, psychology experts say Trump’s narcissistic qualities, us-vs.-them mentality and lead-by-fear approach is straight from the textbook of history’s most notorious cults. Republican senators were scared that if they voted to convict Trump of the impeachment charges, he would attack them with nasty nicknames and launch campaigns to discredit them, according to Sen. Sherrod Brown (D-Ohio), who wrote an op-ed for The New York Times.

And they were right to be worried. In his speech Thursday, Trump referred to the Democrats who tried to remove him from office as “dirty cops,” “leakers” and “liars.” He insulted Romney, saying the senator failed “so badly when running for president,” and he tweeted a video that called him a “Democrat secret asset.”

“They’re afraid to get on his bad side,” said Lalich of Republican senators. “That very much parallels what we see in cults where people are terrified of, you know, being caught out in any kind of expression of doubt or mistrust of the leader.”

Protecting Their Leader With Lies And Mental Gymnastics

Of course, it’s normal for party members to try and keep their leader in power. The political futures of many Republicans are tied to Trump and they will do whatever it takes to protect their careers, said Timothy Miller, a religious studies professor at the University of Kansas who studies group-think. He points out that during President Bill Clinton’s impeachment trial, no Democrats voted against the president.

But there are some key differences as to how senators handled the two impeachments. Democrats didn’t deny what Clinton had done ― they argued that his affair with Monica Lewinsky didn’t merit being kicked out of the White House and proposed that he should instead be censured. While some Republicans have acknowledged, in the face of overwhelming evidence, that Trump is guilty of offering the Ukrainian government a quid pro quo to investigate former Vice President Joe Biden, others have denied that reality.

Before the trial even started, Sen. Lindsey Graham (R-S.C.) said he had already decided the president was not guilty: “I’m not trying to pretend to be a fair juror here,” he told CNN. Rep. Debbie Lesko (R-Ariz.) denied that Trump asked the Ukrainian president to investigate Biden, his political rival, and Sen. Jim Inhofe (R-Okla.) said there was “no evidence of a quid pro quo.”

This type of denial and close-minded attitude mimics how cult members blindly follow their leaders after being indoctrinated. Trump thinks he is above the law said Steven Hassan, a mental health counselor and author of “The Cult of Trump.” “If [Trump] says ‘I did nothing wrong,’ everyone should accept that.”

Cult members experience cognitive dissonance when presented with facts that contradict their beliefs, said Lalich. If Republican senators believe that Trump is good for America, they will work hard to ignore information that would shatter their worldview.

“They’ll shut out whatever’s happening in reality,” she said, “to keep themselves safe within this little cocoon that they’ve built around themselves.”

It’s common for members to use outright lies and mental gymnastics to protect their leader, and themselves. The mentality is that the “end justifies the means,” according to Daniel Shaw, a psychotherapist who specializes in cults. For Republicans, that means keeping Trump in power at all costs.

“Scientology operates in the same way,” he said. “Members are immediately dispersed to deny any wrongdoing and to make false claims.” They create alternate realities to discredit any narrative that attacks a leader.

Republican attorney Steve Castor, for example, repeatedly parroted a debunked conspiracy theory that the Ukrainian government had interfered with the 2016 presidential election to stop Trump’s victory, and Sen. Tom Cotton (R-Ark.) insisted that the claim was true. Multiple Republican congressmen said Biden could not be considered a political opponent, which is obviously false. Despite the fact that the Constitution addresses why foreign interference is an impeachable offense, Sen. Mike Lee (R-Utah) said, “This is exactly the sort of thing the American people elected President Trump to do.”

Once the trial was done, Trump attacked his opponents and Romney in a way that resembles how cult leaders pit their members against everyone else, said Lalich.

This divisive mentality helps bind group members together and makes everything on the outside seem “horrifying and evil.”

“A healthy organization needs to allow for dissent and for asking questions,” said Hassan. “When any organization treats people like traitors for following their conscience or following an oath, that to me is a telltale sign of a mind control cult.”