"I didn't suggest a database-a reporter did. We must defeat Islamic terrorism & have surveillance, including a watch list, to protect America," Trump tweeted early Friday afternoon.
The controversy began Thursday morning when Trump, who also said this week that he would consider shutting down mosques, told Yahoo News
that "we're going to have to look at a lot of things very closely" when asked about a national database for Muslims.
Later in the day, at a campaign stop in Newton, Iowa, Trump told NBC News
he "would certainly implement that. Absolutely," when asked about a national registry of Muslims. "There should be a lot of systems, beyond databases."
But soon after, Trump told CNN's Sara Murray he didn't "know where you heard that" when asked about a national registry for Muslims.
"Yahoo News asked you about it, you didn't rule it out," Murray said as Trump worked a ropeline after the event.
"No, I never -- I never responded to that question," Trump said.
"So would you not support it?" Murray asked.
"I never responded to that question, Sara," Trump said.
He added that he didn't "know who wrote it," referring to the Yahoo News article, and declined to answer a follow-up question from Murray about whether he would "support something like that," referring to a Muslim database. He also declined to respond when Murray asked "what's your view of it?" as he continued down the ropeline.
'That's just wrong'
Trump's apparent call for a registry found little support, even among fans and erstwhile allies in the Republican field.
"I'm a big fan of Donald Trumps, but I'm not a fan of government registries of American citizens," said Texas Sen. Ted Cruz in a rare break with the Republican front-runner. "The First Amendment protects religious liberty, and I spent the past several decades protecting the religious liberty of every American."
Jeb Bush said Trump's comment and other proposals, including one from the Democratic mayor of Roanoke, Virginia to place Muslims in internment camps were "just wrong."
"When you talk about internment, you talk about closing mosques, you talk about registering people -- that's just wrong," Bush said on CNBC's "Squawk Box."
Ohio Gov. John Kasich, whose super PAC recently launched the most expensive attack on Trump of the campaign, said that now was the time for Americans to unite.
"Those who want to divide and impose tests, religious tests, where people are going to go and register for deportation squads that are going to try and go into the neighborhoods and ship people out of this country," Kasich said. "We don't need division in America. We need to be united. We don't need to be just Republicans or Democrats or liberals or conservatives. We are Americans, and we need to act like we're Americans. And we can fight and we can disagree with others, but we respect them. And we love them."
Even Trump supporters at his Friday rally at Wofford College in South Carolina were a little leery of the idea of registering U.S. citizens.
John Lillie, a 53-year-old insurance agent from Charlotte who was attending the event with his wife, said he feared exacerbating racial tensions. The government should certainly do more to monitor individuals on terror watch lists and communicate with allies like France, Lillie said, but the creation of a database was a step too far.
"I deal with Muslims and people from India and of all walks of religion and all different faiths. Some of them are the most genuine, caring, friendly people," he said. "It would cause a division, if there's already not enough of interracial division and racism and stuff now. That would just throw gas in the fire. That's not something we should be doing as Americans."
His wife, Bonita Lillie, also opposed the idea, calling it "dangerous."
But other Trump supporters saw his logic and fear radicalization in the U.S.
"I don't believe all Muslims are bad. But anybody can turn bad and you've got to be able to locate them and know where they're at," said Bickie Mason, a 64-year-old contractor and Trump supporter from Lyman. "We've got to protect this country. It's bad."
Democratic candidates pounced on Trump's proposal Friday. Bernie Sanders said Trump should be "ashamed of himself."
"This is an outrageous and bigoted statement," Sanders said in a statement. "Mr. Trump should be ashamed of himself. We will not destroy ISIS by undermining the Constitution and our religious freedoms."
And Democratic front-runner Hillary Clinton, retweeting a New York Times article on the database controversy, called Trump's remarks "shocking rhetoric."
"This is shocking rhetoric. It should be denounced by all seeking to lead this country. -H," she tweeted.