LANSING, Michigan: US presidential candidate Donald Trump on Tuesday defended a gesture he makes at his rallies in which he raises his right hand in a salute that has been compared by some to the Nazi salute.

Speaking to NBC, Trump called the accusations “ridiculous” and said his supporters call on him to make a gesture as if he’s swearing in for the presidency.

“I didn’t know it was a problem,” Trump said. “Sometimes we’ll do it for fun.”

Trump’s staying power with white, working-class voters was tested Tuesday in Michigan, the first industrial state primary in the four-man race for the Republican nominating contest.

The New York billionaire has appealed to those voters by opposing international trade deals and supporting a wall along the US-Mexico border to keep out immigrants who are seen as competitors for jobs in the industrial economy.

With an eye on the November general election, Trump contends he can put Midwestern, Democratic-leaning industrial states such as Michigan and Wisconsin in play for Republicans.

The Republican party is in near-civil war after Trump came from nowhere last summer but now holds first place over ultra-conservative Texas Sen. Ted Cruz, one-time tea-party favorite and Florida Sen. Marco Rubio and the more moderate Ohio Gov. John Kasich.

Trump leads with 384 delegates, followed by Cruz with 300, Rubio with 151 and Kasich with 37. Winning the Republican nomination requires 1,237 delegates.