Has Donald Trump finally crossed the line?

The Republican front-runner was roundly condemned by his rivals for the GOP presidential nomination for his call on Monday to ban Muslims from entering the U.S. until politicians can “figure out what is going on.”

Businesswoman Carly Fiorina and retired neurosurgeon Ben Carson will both hold rallies in Atlanta on Tuesday, a day after Trump's unprecedented call for a "complete and total shutdown" of the borders to those who believe in the Islamic faith.

“Until we are able to determine and understand this problem and the dangerous threat it poses, our country cannot be the victims of horrendous attacks by people that believe only in Jihad, and have no sense of reason or respect for human life,” Trump said in a statement released by his campaign.

The remarks came hours after President Barack Obama used a primetime address to express concern about the escalating rhetoric aimed at Muslims, who he said are among America's staunchest allies.

“We cannot turn against one another by letting this fight be defined as a war between America and Islam. That, too, is what groups like ISIL want,” he said, using an acronym for the Islamic State. “ISIL does not speak for Islam. They’re thugs and killers. Part of a cult of death.”

Fiorina, a former Hewlett-Packard executive, tied Trump’s remarks to Obama’s speech.

“Unfortunately I think Donald Trump’s over-reaction is just as dangerous as Obama’s under-reaction,” said Fiorina, who headlines a town hall at Georgia Tech at 3:30 p.m.

And Carson, through a campaign spokesman, said the candidate would not support a religious litmus test to enter the country. He’s set to hold a rally at the Cobb Energy Center at 7:30 tonight.

“Everyone visiting our country should register and be monitored during their stay as is done in many countries,” he said in a statement. “I do not and would not advocate being selective on one’s religion.”

Other candidates took their criticism further.

Former Florida Gov. Jeb Bush declared Trump to be “unhinged” while Sen. Marco Rubio called the ban “offensive and outlandish.” Ohio Gov. John Kasich said it was “another reason why he is entirely unsuited to lead the United States.”

On the Democratic side of the ledger, frontrunner Hillary Clinton pronounced the idea “prejudiced and divisive.