Some rivals say the plan to bar Muslims is "offensive" and "unhinged." Some pundits have called it "unconstitutional." But experts say the Constitution gives Congress leverage on whom to let in.
Paul Ryan says freedom of religion is a fundamental, constitutional principle. Ryan also speaks up for Muslims, "the vast, vast, vast, vast majority of whom are peaceful," he says.
One of the reactions from people in Muslim-majority countries such as Indonesia and Turkey: "[Donald Trump] claims to 'make America great again' by going racist in a country of immigrants?!"
The current leader for the GOP presidential nomination received a standing ovation from a crowd in South Carolina after he read aloud his statement to ban all Muslims from entering the U.S.
In his most drastic and controversial statement yet, Trump calls for a stop on any Muslims entering the U.S. "until our country's representatives can figure out what is going on."
Trump had said he'd be endorsed by 100 black religious leaders at a Monday press conference. Instead, there was a 2 1/2-hour meeting, with requests for apologies — and Trump gave none.
In an interview, Donald Trump said people in New Jersey — "where you have large Arab populations" — were cheering when the Twin Towers came down. Police, however, have said it did not happen.