Former Trump Hispanic advisor 'not going down the Trump train any longer'

He was one of Donald Trump's most vocal Hispanic supporters, but now immigration attorney Jacob Monty is pulling that support.

As a member of Trump's National Hispanic Advisory Council, Monty was touting Trump and his immigration plan as recently as Wednesday afternoon. Then, Trump's immigration speech happened Wednesday night in Phoenix, Arizona.

On Thursday, Monty told CNBC, "I'm a never-Hillary person, but I'm not going down the Trump train any longer."

"I was defending him. I thought he heard us a week and a half ago when we talked to him about immigration. He certainly acted like he heard us," he said in an interview with "Power Lunch."

"We were expecting a Republican, pro-business, compassionate speech. And what we got was populist propaganda. … There was no way I could continue to be part of his campaign."

Trump has taken a hard stance on immigration throughout the campaign, pledging to deport the estimated 11 million undocumented immigrants in the country. In August, his campaign assembled the National Hispanic Advisory Council, and recently there was talk he may soften his stance on immigration.

However, in his highly anticipated speech Wednesday night in Arizona, Trump said that illegal immigration has sapped jobs and prosperity from low-skilled American workers. While he didn't commit to removing all of the undocumented immigrants, he said "anyone who has entered the U.S. illegally is subject to deportation."

The speech "disparaged immigrants that are welders, carpenters, bakers and butchers. Those people are doing jobs that Americans aren't able to do because there's not enough Americans or Americans don't want to do those jobs," said Monty.

"He made it sound like unless you have a college degree that you're not worthy of being here, and that's just nonsense," he added.

Meanwhile, Trump's demeanor was more subdued during his press conference earlier Wednesday with Mexico President Enrique Pena Nieto.

"He looked like a champion going to Mexico. He looked presidential. He was tackling the problem. That's who I thought was going to show up in Phoenix," said Monty.

His message to Trump — get rid of the populist advisors who are saying you have to be anti-immigrant, because that is a losing strategy.

"Most immigrants are law-abiding people doing jobs that no one else wants to do. Embrace them. That's the American dream, starting at the bottom," he said.

— CNBC's Jacob Pramuk contributed to this report.