The US is "under siege by a moron", according to rock legend Bruce Springsteen, who described Accusing the real estate mogul of offering "simple answers to complex problems", he said the Republican presidential candidate was "pushing people beyond democratic governance".
"Once you let those genies out of the bottle, they don't go back in so easy, if they go back in at all,"
The Boss told Rolling Stone magazine. "The ideas he's moving to the mainstream are all very dangerous ideas – white nationalism and the alt-right movement."
Calling some of the things Trump had done "outrageous", Springsteen criticised him for not immediately disavowing David Duke, the prominent white nationalist and former Grand Wizard, or leader of the Ku Klux Klan.
"These are things that are obviously beyond the pale for any previous political candidate," he said. "It would sink your candidacy immediately."
He added that he thought Hillary Clinton "would be a very, very good president."
In a separate interview with Norwegian/Swedish talk show Skavlan, Springsteen, whose memoir, Born to Run is released next week, called Trump "an embarrassment".
"The absurdity is beyond cartoon-like. But he's gotten close enough so it can make you nervous," he said. "I don't think he's going to win, but even him running is a great embarrassment if you're an American."
He added: "If you've struggled and if you've suffered and you haven't got that piece of the pie, then he can give a very compelling argument… It's just a rich environment unfortunately for a demagogue."
Asked if he'd ever met Trump, he said he had done his best to avoid him.
Springsteen's fellow rocker Jon Bon Jovi, also criticised Trump.
"It's an unbelievable time in American politics and it scares the (blank) out of me," he told the Gigwise music website. "I pray he's not the next president of the United States. It's incredible that the man can lie to you. You tell him here's factually what you said that's incorrect and then he tells it the same (way again)."
Bon Jovi, who has campaigned for Democratic candidate Hillary Clinton added that he was hopeful she would win in November.