Attendees of President Donald Trump’s rally in Grand Rapids, Michigan, on Thursday evening broke out into an “AOC Sucks!” chant after Donald Trump’s Jr. ripped into Rep. Alexandria Ocasio-Cortez’s (D-NY) progressive policy positions.

Ahead of Trump's rally in Grand Rapids, Michigan, Don Jr. told the crowd that Alexandria Ocasio-Cortez "three weeks ago didn't know the three branches of government" pic.twitter.com/ZyFNmfIDr3 — Erika Ryan (@erikapryan) March 28, 2019

“Think about the fact that every mainstream, leading Democratic contender is taking the advice of a freshman congresswoman who three weeks ago didn’t know the three branches of government,” Trump Jr. told a fired up crowd before his father’s highly anticipated speech. “I don’t know about you guys, but that’s pretty scary.”

The remarks critical of the freshman congresswoman prompted the crowd to chant “AOC sucks.”

“You guys, you’re not very nice,” the president’s son replied jokingly to the chant “And neither is what that policy would do to this country.”

Trump Jr.’s remarks slamming Ocasio-Cortez come after the Green New Deal, legislation unveiled in February by the freshman New York Democrat and Sen. Ed Markey (D-MA), was blocked by the Senate with most Democrats voting present. The Green New Deal aims to “transform” the U.S. economy with a “10-year national mobilization” to shift away from fossil fuels and replace them with renewable energy sources. An outline and FAQ for the proposal detailed eyebrow-raising goals, which included eliminating the necessity of air travel and “economic security to citizens unable or unwilling to work.” Ocasio-Cortez came under fire for claiming its FAQ, which was sent to NPR and other news outlets, is separate from the Green New Deal’s policy goals.

Several Democrat presidential contenders, including Sens. Kamala Harris (D-CA), Elizabeth Warren (D-MA), and Cory Booker (D-NJ) have voiced support for the plan. At a campaign stop in Iowa, Booker compared the proposal to fighting Nazis during World War II. “We have to deal with this. Our planet is in peril, and we need to be bold. It’s one of the reasons I signed on to the resolution. I co-sponsored the resolution for the Green New Deal,” he told supporters. “There’s a lot of people blowing back on the Green New Deal. They’re going, ‘Oh, it’s impractical, oh it’s too expensive, oh it’s all of this.’ If we used to govern our dreams that way, we would have never gone to the moon.”

Yet, not all Democrats are thrilled about the Green New Deal proposal, which an analysis released via Bloomberg estimated would cost an eye-watering $93 trillion. Appearing on MSNBC’s Morning Joe in recent weeks, former Virginia Gov. Terry McAullife said the proposal was “unrealistic.”

“I come from a place — there are some great aspirational goals. Climate change is real, we need to be very concerned,” he told host Joe Scarborough. “I took action as governor, record amounts in renewable energy. I’d like to talk about things we can actually get done and things that we have actually done. That’s the difference. All these litmus tests, of this and that. Listen, voters want someone who actually has big, bold ideas, who is going to come in with a gigantic infrastructure plan.”