Trump listens to a question during a town hall event at Rochester Recreational Arena in Rochester, New Hampshire.

AFP/Washington
Democratic presidential candidates have slammed Donald Trump 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 White House hopeful to say that he would have corrected the man immediately.
“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 billionaire real estate magnate’s campaign stop late on 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.
While Trump did not himself address Obama’s religion or citizenship on Thursday, his failure to shut down the questioner highlighted a 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.
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”.
Trump’s campaign manager Corey Lewandowski said that 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.”
Trump was due to attend a presidential candidate forum in South Carolina yesterday, but his campaign abruptly cancelled his appearance, citing delays to a “significant business transaction”.
Democratic Party chairwoman Debbie Wasserman Schultz, a congresswoman from Florida, blasted Thursday’s incident as “horrendous but unfortunately unsurprising”.
Bernie Sanders, the liberal US senator challenging Clinton for the Democratic nomination, demanded Trump “apologise to the president and American people for continuing the lie that the president is not an American and not a Christian”.
Most of the 16 Republican presidential candidates remained publicly silent on the issue as of mid-day yesterday, 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 on the 2008 campaign trail when he was 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, taking the microphone away from the woman.
In 2011 Trump repeatedly called into question 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 continued to express scepticism about it.
Many Americans remain sceptical too.
According to a recent CNN/ORC poll, 29% of Americans believe Obama is a Muslim, with that number rising to 43% among Republicans.
Concerns about anti-Muslim sentiment in the United States flared this week after a Muslim teen 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.