Republican front-runner Donald Trump urged his supporters to raise their right hand and vow to support him, at a campaign rally on Saturday, drawing comparisons to a Nazi rally amid allegations by critics that a vote for him is tantamount to a vote for Hitler.

Photos from the event in Orlando, Florida, earned Trump dozens of comparisons to Nazi dictator Adolf Hitler, with social media users saying the gesture was reminiscent of the “Heil Hitler” salute.

“Let’s do a pledge. Who likes me in this room?” Trump said at the rally. “Raise your right hand. I do solemnly swear that I — no matter how I feel, no matter what the conditions, if there’s hurricanes or whatever — will vote, on or before the 12th, for Donald J. Trump for president.”

The audience, including a man dressed as a wall, eagerly complied. And one man raised his dog’s paw.

Donald Trump at a rally in Orlando, Florida on March 5, 2016.  (screen capture: YouTube)

Donald Trump at a rally in Orlando, Florida on March 5, 2016. (screen capture: YouTube)

“Don’t forget you all raised your hands,” Trump said. “You swore. Bad things happen if you don’t live up to what you just did.”

It wasn’t long before photos of the spectacle caused a stir on social media.

It wasn’t the only comparison of Trump to history’s greatest monster.

Over the weekend, comedian Louis C.K. dubbed Trump “Hitler,” and called him “dangerous” and an “insane bigot.”

“Please stop it with voting for Trump,” C.K. wrote in an email to fans. “It was funny for a little while. But the guy is Hitler. And by that I mean that we are being Germany in the ’30s. Do you think they saw the s–t coming? Hitler was just some hilarious and refreshing dude with a weird comb over who would say anything at all.”

The comedian is far from the only person to criticize Trump for his stances on migrants and others, warning that it recalls history’s darkest periods.

Psychologists say there has been an uptick in Trump-induced anxiety, the Washington Post reported over the weekend..

“Part of the reason he makes people so anxious is that he has no anxiety himself. It’s frightening. I’m starting to feel anxious just talking about him,” said NY-based psychologist Judith Schweiger Levy.

Fellow psychologist Mary Libbey told the paper her patients didn’t report higher levels of Trump-related stress, but she did.

“It helps me to talk about it,” she said. “I’m terrified that he could win. His impulsivity, his incomplete sentences, his strange, squinty eyes — to my mind, he’s a loosely held together person.”