Donald Trump called Monday for a "total and complete shutdown of Muslims entering the United States," an idea swiftly condemned by his rival GOP candidates for president and other Republicans.
The proposed ban would stand "until our country's representatives can figure out what is going on," his campaign said in a statement.
The statement added that Trump's proposal comes in response to the level of hatred among "large segments of the Muslim population" toward Americans.
"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 the statement.
At an evening rally in South Carolina, Trump supporters cheered and shouted in support as he read his statement. Trump warned during his speech that without drastic action, the threat of attacks is "going to get worse and worse."
"As he says, we have to find out who they are and why they are here," Rod Weader, a 68-year-old real estate agent from North Charleston who attended the rally and said he agreed with Trump's plan "150 percent." ''Like he said, they are going to kill us and we've got to stop it."
The frontrunner made those statements right after Texas Director Corbin Casteel spoke with NBC 5 Political Reporter Julie Fine.
But Casteel says Trump speaks for Trump. Casteel says their operation is up and running in Texas, with tens of thousands of volunteers.Texas is not a winner-take-all state, and there are now Trump Co-Chairs in each of the congressional district.
Trump is up against Texas Senator Ted Cruz, and Jeb Bush, who was born in Texas.
"Donald Trump is unhinged," Jeb Bush said via Twitter. "His 'policy' proposals are not serious."
John Kasich slammed Trump's "outrageous divisiveness," while Cruz, more measured always cautious about upsetting Trump's supporters, said, "Well, that is not my policy."
Trump's plan also drew criticism from the heads of the Republican Party in Iowa, New Hampshire and South Carolina, the first three states to vote in next year's presidential primaries.
But Casteel says Trump is plenty Texas.
"Donald Trump, he embodies the Texas spirit. He is fiercely independent like Texans. He says what he means and means what he says like Texans, and he is not afraid of a fight like Texans," Casteel said.
The comment quickly drew a response from the Council on American-Islamic Relations, whose communications director, Ibrahim Hooper, told NBC News: "Donald Trump sounds like a leader of a mob, not like a leader of a great nation like ours. He is doing the work of ISIS."
Trump campaign manager Corey Lewandowski said Trump's proposed ban would apply to "everybody," including Muslims seeking immigration visas as well as tourists seeking to enter the country.
He did not respond to questions about whether it would also include Muslims who are U.S. citizens and travel outside of the country, or how a determination of someone's religion might be made by customs and border officials.
In response to a request for additional detail, Trump said via a campaign spokeswoman: "Because I am so politically correct, I would never be the one to say. You figure it out!"
Trump's proposal comes a day after President Barack Obama spoke to the nation from the Oval Office in the wake of the shootings in San Bernardino, California, which Obama said was "an act of terrorism designed to kill innocent people."
The FBI said Monday the Muslim couple who carried out the massacre had been radicalized and had taken target practice at area gun ranges, in one case within days of the attack last week that killed 14 people.
Soon after Trump's announcement, U.S. Secretary of Homeland Security Jeh Johnson called on Americans not to vilify Muslims.
"Now more than ever it is time to work together, build bridges and pursue a stronger union," Johnson said at a press conference after a roundtable discussion with the All Dulles Area Muslim Society, which was already scheduled before Trump's comments.
NBC 5's Julie Fine contributed to this report.