Several top 2020 Democratic contenders are taking shots at South Bend, Ind., mayor Pete Buttigieg.

A New York Times report reveals that the widespread annoyance comes after Buttigieg declared last week that the Democratic primary race was a "two-way" race between him and Sen. Elizabeth Warren (D., Mass.).

Former vice president Joe Biden—who leads Buttigieg in virtually every poll—responded with mockery, joking to reporters, "Well, good, I hope they do well."

It wasn't the first time that Biden had smirked at Buttigieg. After the 37-year-old candidate launched his exploratory committee in January, Biden greeted him as "Mr. President" during a meeting with several other mayors, in a "voice dripping with condescension," according to the Times.

Other candidates have mocked Buttigieg as well, citing his youth and relative lack of political experience as disqualifications for his candidacy.

Sen. Kamala Harris (D., Calif.) called his comment about Warren "naive." Sen. Amy Klobuchar (D., Minn.) said that if she was running with his levels of political experience, she wouldn't be taken "seriously." And former congressman Beto O'Rourke called Buttigieg "a human weather vane," who represented the worst of politics, according to aides.

Former secretary of housing and urban development Julián Castro said that Buttigieg's lack of popularity with minorities makes him a bad choice for Democrats.

"It is very risky to nominate a candidate that can't attract black and Latino voters," Castro told the Times. "He's going by the old playbook of following the focus groups, going by what political consultants tell you. If we've learned anything from Donald Trump, unfortunately in a bad way, it's that focus grouping and poll testing ain't the way that you're going to win."

Buttigieg also drew the ire of Warren last week when he called her a divisive figure in the party.

"I'm not running some consultant-driven campaign with some vague ideas that are designed not to offend anyone," Warren responded.

Buttigieg rose to the top of the Democratic field in the spring, promising to be a fresh face for the Democratic Party. After a scandal-ridden summer, he rebranded himself as a moderate alternative to candidates such as Biden and Klobuchar.

Buttigieg's response to fellow candidates' criticism has been curt: "I'm not going to comment on the emotions of my competitors," he said.