He has called for a temporary ban on Muslims entering the United States, entertained the idea of starting up a registry for Muslims and proposed surveillance of certain mosques - yet presumptive Republican nominee Donald Trump is not writing off the Muslim vote.
In the weeks since he became the last man standing in the Republican race, Mr Trump's campaign has actually started quietly reaching out to Republican Muslims to try to bring them back into the fold.
A Muslim adviser to the tycoon, Mr Walid Phares, has been courting influential conservative Muslim activists, and at least two different grassroots-level groups are trying to promote Mr Trump among the community.
The argument they are putting forward is that Mr Trump has the right social and economic policies, while his more fiery rhetoric has been misconstrued as anti-Muslim.
Mr Sajid Tarar, 52, a Pakistani immigrant who set up a group called Muslims for Trump, told The Straits Times that he can support the proposed ban on Muslims if it means keeping Americans safe. "Whatever is required to ensure safety for American people, I'll support that.
"Any time something goes wrong here, if there is an incident, we start saying, 'I hope he is not Muslim'. We are living under threat. We want to see America strong, we want to see America safe because we are part of the American fabric," he said.
Mr Tarar has been reaching out to Muslims through his personal network and he is also trying to spread the word on social media. He said his organisation now has about 500 members and he planned to hold a fund-raiser soon in Washington for Mr Trump, who has secured the 1,237 delegates he needs to clinch nomination, according to an Associated Press tally on Thursday.
Mr Tarar said that while it remains an "uphill battle", he is making progress. "People used to look at me like I'm a traitor, but it is changing," he said.
Similarly, Mr Tom Harb, a 56-year-old Lebanese-American who co-founded the American Middle East Coalition for Trump, said that the image of Mr Trump as anti-Muslim was not true. "The perception has been set by Democrats and the media tends to have that opinion, but when we engage in discussion and spell out each scenario, then there is more understanding and acceptance," he said.
Then there are others like conservative blogger Shireen Qudosi, who said she is supporting Mr Trump because of his straight-talking nature. "The day-to-day loss of values and honour in American society is a greater burden than anything Trump says. As a woman, I don't need my emotions cradled. What I need is honesty," wrote Ms Qudosi, who is one of the activists approached by Mr Phares.
And while recent efforts are slowly paying off, most analysts say Mr Trump is unlikely to get a significant chunk of the some two million Muslim-American voters.
A survey of Muslim voters in February by the Council on American- Islamic Relations showed how difficult the task is for Mr Trump. Some 51 per cent of respondents said they would vote for Democratic front runner Hillary Clinton, 22 per cent backed Senator Bernie Sanders, but only around 7 per cent supported Mr Trump.
Mr Trump has been moderating his position on his proposed ban on Muslims entering the US. The businessman refused to directly bring up the policy on Thursday during a press conference in North Dakota.
"We are looking at a lot of different things. We have a radical Islamic terrorism problem. It's a worldwide problem, not just this country, and we have to find a solution," he said when asked directly if he still supports the policy.
Earlier this week, his campaign chief Paul Manafort was more explicit about Mr Trump's softening stance. He said in an interview with the Huffington Post: "He operates by starting the conversation at the outer edges and then brings it back towards the middle. Within his comfort zone, he'll soften it some more."