WATCH: GOP crowd cheers when mother-in-law of new Trump deputy calls immigrants ‘rats and roaches’

Donald Trump has hired a notorious "Clinton hunter" David Bossie to serve as his deputy campaign manager -- and Democratic activists are ready to push back.

The Democratic Coalition Against Trump group unearthed video of Bossie's mother-in-law delighting a Republican crowd last year by comparing immigrants to vermin at an event organized by the GOP operative.

Bossie, who was then president of Citizens United, put together the 2015 South Carolina Freedom Summit, and GOP pollster Frank Luntz then interviewed the organizer's mother-in-law.

"One man, one vote," she says. "People are coming in this country across the borders like rats and roaches in the woodpile. We’ve got a state like Minnesota that says it’s not our business to check them out, we just register them. We’ve got to get control. That’s what they need to know."

Luntz then reaches for the microphone, but the woman continued her screed.

“Years ago, I might have been a Democrat,” she says. “But I saw the problem and I went to the Republican Party. I didn’t wait for them to come looking for me. Why do these young people have to be solicited? We are all intelligent people. We need to be voting our convictions and choose a party.”

Luntz then asked the GOP crowd whether they would vote for the woman for president -- and the crowd cheered enthusiastically.