Ahead of his father's rally in Michigan on Thursday, Donald Trump Jr. took the stage to rile up the crowd, boast about his father's accomplishments and attack his Democratic foes, which led to chants of "AOC sucks!" against Rep. Alexandria Ocasio-Cortez.

"Think about the fact that every mainstream leading Democratic contender is taking the advice of a freshmen congresswoman who three weeks ago didn't know the three branches of government," Trump Jr. told the crowd as he discussed Ocasio-Cortez's Green New Deal, a climate change bill that failed in the Senate this week.

"I don't know about you guys but that's pretty scary," the president's eldest son said as the crowd started to chant, "AOC sucks! AOC sucks!"

Trump chuckled then told the crowd: "You guys, you're not very nice and neither is what that policy would do to this country."

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Ocasio-Cortez, a freshmen Democrat from New York, has been a favorite of conservatives, who have targeted her progressive policies and pinned them as a radical trend within the Democratic Party. She has become a progressive superstar and captured an enthusiastic following due to her fierce social media posts and congressional speeches.

Trump Jr. specifically brought up the congresswoman while discussing her Green New Deal bill, an aspirational proposal to confront climate change and address social justice. Conservatives have ridiculed the plan as a socialist fantasy — one that they say would bankrupt the nation.

Spurred by government reports warning of drastic consequences of climate change, Ocasio-Cortez and Sen. Ed Markey, D-Mass., unveiled the proposal in February.

It called not only for combating climate change by eliminating carbon emissions caused by fossil fuels and shifting the economy to one powered by renewable fuels but also prescribed a broad platform supporting free housing, medical coverage and higher education for all Americans.

'Nonsense':Defending Green New Deal, Ocasio-Cortez says GOP Sen. Mike Lee doesn't take 'job seriously'

More:Ocasio-Cortez says she isn't putting moderate Democrats in a tough spot. They disagree

Trump Jr. ridiculed the plan in front of the thousands gathered for Trump's rally and blasted Democrats in Congress who are running for president in 2020 who have voiced support for the measure.

"What about brilliant policies like the Green New Deal?" Trump Jr. asked the crowd. "What's scarier about the Green New Deal is that every mainstream Democrat leading presidential contender is like 'this is a great idea!'"

President Trump's Michigan event marked his first campaign rally since a summary of special counsel Robert Mueller's investigation into the 2016 election found his campaign did not conspire with Russia to influence the outcome. The president has repeatedly touted that summary in Washington, even as Democrats press for more detail.