Sen. Marco Rubio, R-Fla., escalated his feud with Transportation Secretary Pete Buttigieg on Sunday, saying Buttigieg is working for the agenda of "Marxist misfits."

Buttiegieg hit out at Rubio early Sunday over the senator's opposition to codifying gay marriage. Rubio fired back in a video on Twitter, mocking the Biden administration official for telling Americans suffering under high gas prices to buy expensive electric cars.

"We have a transportation secretary named Pete Buttigieg who believes that highways can be racist; who believes that $5 gas—which is killing working Americans—is a great thing because that means people are gonna drive less, or because everyone is now gonna go out and buy a $65,000 electric car with a Chinese battery in it," Rubio said.

"I'm gonna focus on the real problems. I'm not gonna focus on the agenda dictated by a bunch of affluent, elite liberals and a bunch of Marxist misfits who sadly today control the agenda of the modern Democratic Party," he added.

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Pete Buttigieg issuing remarks

Transportation Secretary Pete Buttigieg speaks during a briefing at the White House, May 16, 2022. (AP Photo/Susan Walsh, File)

Rubio had previously called the push to codify gay marriage in Congress a "stupid waste of time."

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Democrats began pushing the bill after the Supreme Court struck down Roe v. Wade, causing some within the party to fear that Obergefell v. Hodges, the ruling creating a right to gay marriage, could fall as well.

"I don't think we should be spending time on a non-issue and a non-problem," Rubio said Saturday. "It's as simple as that. I just don't. Not when people are paying $4.66 for gas. Not when inflation and prices for some of the most basic goods and services in our country are crushing middle-class Americans."

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"This is just not real. It's a fake problem. I don't vote for fake problems. I don't vote to solve problems that don't exist. It's important for the priorities of the people in Washington to be the priorities of the people that sent us there," he added.

The same-sex marriage bill passed through the House of Representatives last week and now must gain the support of at least 10 Republicans to pass the Senate.