WASHINGTON - Democratic presidential candidates joined the White House in slamming Donald Trump Friday for failing to challenge a questioner who wrongly claimed President Barack Obama was a Muslim and not a US citizen.
The campaign trail exchange triggered the latest uproar over the Republican frontrunner's regard for minorities in America and prompted at least one Republican presidential hopeful to say he would have corrected the man immediately.
And in a move uncharacteristic of the media-savvy billionaire, Trump cancelled a public appearance scheduled for Friday.
"We have a problem in this country, it's called Muslims. We know our current president is one, you know he's not even an American," an unidentified man told Trump at the real estate magnate's campaign stop late Thursday in Rochester, New Hampshire.
Trump chuckled and interrupted him to say, "We need this question. This is the first question." "Anyway, we have training camps growing where they want to kill us," the man resumed. "That's my question: When can we get rid of them?" "A lot of people are saying that, and a lot of people are saying that bad things are happening out there," Trump responded.
Trump quickly moved on to another questioner, without addressing the man's assertions about Obama - which reflect a lingering misconception among the American public.
The incident highlighted Trump's propensity to court controversy when it comes to minorities and immigrants.
When he launched his campaign in June he attacked Mexican immigrants as "rapists" and killers, and has repeatedly denigrated foreign nationals who enter the country and give birth to so-called "anchor babies" entitled to claim US citizenship.
'Cut it out'
Thursday's exchange prompted outrage from Democrats and demands for an apology.
Democratic frontrunner Hillary Clinton tweeted that Trump's failure to denounce the "hateful rhetoric about Muslims is disturbing, & just plain wrong. Cut it out." The White House described the views expressed as "offensive" and symptomatic of a broader trend in the Republican party.
"Is anyone really surprised that this happened at a Donald Trump rally?" White House press secretary Josh Earnest said.
"The people who hold these offensive views are part of Mr Trump's base, and Mr Trump would be the first to tell you that he has the biggest base of any Republican politician these days." Trump's campaign manager Corey Lewandowski said his candidate did not hear the question about Obama's religion.
"All he heard was a question about training camps, which he said we have to look into," Lewandowski told CNN.
"The media want to make this an issue about Obama, but it's about him waging a war on Christianity."
'Horrendous but unsurprising'
Trump was due to attend a South Carolina forum Friday, but his campaign abruptly cancelled his appearance, citing delays to a "significant business transaction" that Trump was negotiating.
Democratic Party chairwoman Debbie Wasserman Schultz blasted Thursday's incident as "horrendous but unfortunately unsurprising." Bernie Sanders, the liberal senator challenging Clinton for the Democratic nomination, demanded Trump "apologise to the president and American people." Most of the 16 Republican presidential candidates steered clear of the issue publicly, but New Jersey Governor Chris Christie spoke out.
"If somebody at one of my town hall meetings said something like that I would correct them and say, 'No, the president's a Christian and he was born in this country," Christie told NBC.
Republican nominee John McCain notably did just that in 2008 when confronted by a supporter who worried that Obama was "an Arab," and his handling of the situation earned wide praise.
"No ma'am. He's a decent family man and citizen who I just happen to have disagreements with on fundamental issues, and that's what this campaign is all about," McCain said as he took the microphone away from the woman.
The White House's Earnest said it was "too bad that ( Trump) wasn't able to summon the same kind of patriotism that we saw from Senator McCain."
In 2011, Trump repeatedly questioned Obama's citizenship and demanded the president release his birth certificate to prove he was not born in Kenya, as many in the fringe "birther" movement suspect.
Obama, who was born in Hawaii, released the document, but Trump maintained skepticism about it.
Many Americans remain doubtful too. According to a recent CNN/ORC poll, 29 per cent of Americans believe Obama is a Muslim, with that number rising to 43 per cent among Republicans.
Concerns about anti-Muslim sentiment flared this week after a Muslim teenager was arrested at his Texas school when a teacher mistook his homemade clock for a bomb.
The boy won a surge of public support and Obama has invited the 14-year-old to the White House.