NEW YORK (AFP) - Donald Trump's hardline stance on immigration after two bombings in the New York area again sparked debate on the White House campaign trail on Tuesday (Sept 20), as his son sparked a firestorm by comparing Syrian refugees to lethal candies.
The Republican presidential hopeful's uncompromising position on illegal migrants - even calling them a dangerous "Trojan horse" who enter the country with the aim of doing harm - is inextricably linked with his meteoric political rise.
Most Republicans approve of his tough talk, with polls showing that a majority of party members agreed with his call last December to bar Muslims from entering the United States.
Since then, Trump has refrained from specifically targeting Muslims, but he has championed police profiling of suspects and promised to bar immigrants and travellers from certain countries deemed dangerous, like Syria.
The candidate has repeatedly warned of the risks posed by Syrian refugees, citing the arrival in Europe of Islamic State in Iraq and Syria (ISIS) operatives disguised as simple refugees, and says US immigration officials are not properly screening new arrivals.
But immigration is nevertheless not one of the major issues on the minds of voters, placing only fourth according to a recent CBS/New York Times poll, making it unclear if Trump, 70, can use it to persuade those who are still undecided.
But national security and the anti-terror fight are number two on that list, and with less than 50 days to go before Election Day on Nov 8, Trump is attempting to blur the lines between the two issues.
"This is a question of qualify of life," Trump told a rally in key swing state Florida on Monday. "We want to make sure we are only admitting people in our country who love our country."
Trump's son Donald Jr, one of his surrogates on the campaign trail, has meanwhile courted controversy with a tweet comparing Syrian refugees to a bowl of multi-coloured Skittles candy - some of them lethal, but not to the naked eye.
"This image says it all," he said on Twitter, with a picture of a white bowl filled with the popular sweets.
Written above the image is: "If I had a bowl of skittles and I told you just three would kill you. Would you take a handful? That's our Syria refugee problem."
Trump Jr thus argued that it is too dangerous to welcome migrants when a tiny number of them could later launch attacks. The man accused of planting bombs in both downtown Manhattan and near a race in New Jersey is a naturalised American of Afghan descent.
At his rallies, Trump Sr has repeatedly recited the lyrics to a 1960s song, The Snake, which recounts how a woman who aided an injured snake ended up being bitten, and used the Trojan Horse imagery to warn of hidden dangers.
"We cannot let this evil continue. Cannot do it," he said on Monday.
"Nor can we let the hateful ideology of radical Islam, its oppression of women, gays, children and non-believers, be allowed to reside or spread within our country."
Wrigley, the maker of Skittles, on Tuesday criticised Trump Jr's tweet.
"Skittles are candy. Refugees are people. We don't feel it's an appropriate analogy," a company statement said.
"We will respectfully refrain from further commentary as anything we say could be misinterpreted as marketing."
Trump's Democratic rival Hillary Clinton, who had no public events scheduled on Tuesday a week after taking a break from campaigning to recover from pneumonia, backs President Barack Obama's position on immigration.
Obama has increased the number of Syrian refugees granted entry to the United States in the face of the brutal five-year war in their homeland.
Her campaign team published the story of an American of Libyan descent, who helps refugees to settle in the US.
"Donald Trump would have kicked my family out of the country," said the man from swing state Ohio, identified as Mohamed G.