The re-emergence of long condemned hate groups has "emboldened" them all over again, which scares Abraham Foxman, the former National Director of the Anti-Defamation League.

"The hate groups in our country for many years were in the shadows, hiding their identity," Foxman told CNN's Newsroom on Saturday. "To see them proud, they were so emboldened with their hatred. They wanted you to hear them. They wanted you to see them, to be intimidated. That was the scary part."

President Trump's fault is this comes because he "destroyed all the taboos," Foxman added.

"I think they feel emboldened by the last election because some of the themes they have for differences is anti-immigrant, xenophobic, this is part of the social discourse in the country,"Foxman said.

"In the last campaign when the president ran for office, he destroyed all the taboos. You want to be a bigot, our constitution allows you to be a bigot in your head, heart, home, but when you act it out, that's a consequence to pay.

"This breaks every taboo. There's no consequences. So the people in Charlottesville, the bigots, feel they are emboldened. It's okay now to publicly demonstrate."

Foxman does not believe President Trump to be supportive of hate groups, and those standing out against them now are a positive, but Trump does need to admit his mistakes – "something I'm not sure he's capable of doing," Foxman said.

"I don't believe he's a racist, no," Foxman said. "It's all about Trump. The crescendo is growing, people are standing up, and one by one, that's the beauty."

Foxman concluded with a call for President Trump to delegitimize the resurfaced hatred all over again.

"He needs to say I made a mistake, something I'm not sure he's capable of doing," Foxman said. "He needs to apologize, not from prompters, but from his gut.

"He needs to fix it because he's part of the reason we're in this mess now of giving and emboldening Nazis and bigots to say, 'this is our message, it's out there, it's legitimate.' We have to make it illegitimate again."