Scott and DeSantis threatened to deport students who voice support for Hamas as experts have said antisemitism is on the rise.

"To every student who've come to our country on a visa to a college campus, your visa is a privilege, not a right," Scott said. "To all the students on visas who are encouraging Jewish genocide, I would deport you from those campuses."

"I was the first presidential candidate to say, 'If you are here on a student visa as a foreign national, you're making common cause with Hamas, I'm canceling your visa, and I'm sending you home, no questions asked,'" DeSantis said.

Haley also went after college administrators for what she said was insufficient action to protect Jewish students.

"No person should ever feel in danger like this. And this is what I would say about our college presidents, is if the KKK were doing this, every college president would be up in arms."

Some of the demonstrations seen in the U.S. have been in support of the Palestinian people living in the Gaza and West Bank territories. U.S. officials have repeatedly said that the terror group Hamas is not representative of all Palestinians.

-ABC News' Tal Axelrod

Asked what they would be urging Israeli Prime Minister Benjamin Netanyahu to do if they were president, the candidates were united on Israel's right to defend itself against the terrorist group Hamas.

DeSantis said he would tell Netanyahu to "finish the job once and for all with these butchers, Hamas."

"The only thing we should be doing is supporting them in eliminating Hamas," Haley said, while also stressing the need to bring hostages home.

Ramaswamy said he would tell Netanyahu to "smoke those terrorists on his southern border, and I'll tell him as president of the United States, I'll be smoking the terrorists on our southern border."

Scott said he would tell President Joe Biden that diplomacy is a "weak strategy."

"You cannot negotiate with evil. You have to destroy it," he said.

Christie echoed the other candidates, saying, "You must make sure that Hamas can never do this again."

-ABC News' Meredith Deliso

Ramaswamy is being very pointed out of the gate, and it’s a bit of a risky strategy -- he could be seen as more of a bully and it could increase negative perceptions of him. That has already happened to him in one debate so far this year. He came off strong in the first debate, too, and his unfavorable rating increased from 13% to 32% after it, according to a poll by 538/Washington Post/Ipsos.

-Analysis by Nathaniel Rakich of 538

This is unverified.

Trump ally Rep. Marjorie Taylor Greene, R-Ga., shared information in June she said she read in an FBI form about a bribery allegation involving Joe Biden, then vice president, his son Hunter and a Ukrainian energy executive.

The FBI filled out the form, known as an FD-1023, in June 2020 after hearing allegations from an informant. The FBI has said such forms contain unverified information. Multiple news outlets have reported that law enforcement have been unable to substantiate the allegations.

-Analysis by Aaron Sharockman of PolitiFact

NBC's Lester Holt posed the first question of the night to DeSantis, asking him why he should be the nominee instead of Trump.

"Now if you look where we are now, it's a lot different than we were in 2016 and Donald Trump's a lot different guy than he was in 2016," the Florida governor said, immediately setting a tone on stage in which the various candidates more bluntly criticized the absent front-runner -- something they had not done throughout much of the early primary campaign.

"He owes it to you to be on this stage and explain why he should get another chance," DeSantis continued. "He should explain why he didn't have Mexico pay for the border wall. He should explain why he racked up so much debt. He should explain why we didn't drain the swamp. He said Republicans were going to get tired of winning. What we saw last night, I'm sick of Republicans losing. In Florida, I showed how it's done."

-ABC News' Alexandra Hutzler