Among a host of controversial comments, he has threatened to ban Muslims from entering the US, and promised to build a wall to prevent immigrants from illegally crossing over the US border from Mexico.
Yet he remains the Republican frontrunner.
Millions of Americans share his extreme views.
Why?
Commentator Jay Kuten points out that Trump is speaking to the frustration, bitterness, and disappointment felt by millions of working-class and middle-class Americans, who hear in his populist anti-establishment comments confirmation of their own anger, as evidence mounts of their exclusion from the American Dream.
Americans living in the Bay are alarmed about Trump's success, and what this success says about their homeland.
They have experienced 30 years of wage stagnation as their well-paying factory jobs got shipped overseas.
Trump has criticised the establishment for not protecting those workers and blasted companies for taking production overseas.
He may have some valid points over these issues but his tactic of blaming certain groups - Mexicans and immigrants - for the problem undermines his argument.
Americans living in the Bay are alarmed about Trump's success, and what this success says about their homeland.
Speaking to the Bay of Plenty Times Weekend, expat Chelsea Gardner, who has traditionally voted Republican, rejects any notion of Trump being an advocate for the people.
"I feel like he's a cartoon character and I'm not impressed with his morals or his ability to lead.
"When he announced his candidacy, I honestly thought it would only last a few weeks, that it was a publicity stunt," she says.
She believes the campaign is bringing to light problems with the US political system, including a lack of moderate candidates, "where the people who get the most attention are the most outrageous".
Trump has a gift for the outrageous.
His stated intention to hit terrorist organisation Isis "hard" is likely to gain him more support following the terror attacks in Brussels.
In an article in the Daily Mail, Piers Morgan asked whether, when it comes to terror, it is time we started listening seriously to Trump. He says strong leadership is needed to tackle the seemingly endless acts of barbarism.
Alternatively, of course, Trump's comments could provoke more terror attacks.
I hope that reason wins in the end, and that the world does not have to grapple with a Trump presidency.
