Former Massachusetts Governor Bill Weld on Sunday defended his recent holocaust analogy in criticizing Donald Trump’s plan to deport undocumented immigrants from the U.S. If elected as president.

Weld, who was named as the Libertarian Party’s vice presidential candidate by Gary Johnson on Thursday, told The New York Times that Trump’s plan to remove the estimated 11 million undocumented immigrants from the U.S. reminded him of “Kristallnacht.”

“I can hear the glass crunching on Kristallnacht in the ghettos of Warsaw and Vienna when I hear (Trump’s plan), honest,” Weld told the NY Times.

In an interview on CNN’s “State of the Union” program, host Jake Tapper asked Weld, “Is that a little strong, you think, to talk about the Holocaust?”

“No, I don’t think so,” Well replied. “I served five years on the U.S. Holocaust Commission by appointment of President George W. Bush. I’m absolutely certain that, as we said in those years, if we don’t remember, we absolutely will forget.And you got to forget a lot of things to think it’s a good idea to round up and deport 11 million people living peaceably, most of them working in America, in the middle of the night. No, not the United States. China, maybe. Not the United States.”

Johnson said on Saturday he wouldn’t have made the Holocaust reference but defended the sentiments behind Weld’s comment.  “What are we going to do? Are we going to go in these homes and take these people out of their homes? Come on. He made that reference. I don’t make that reference, but it’s crazy. It’s off the charts,” Johnson said in an interview with CNN.