A progressive political group that boosted New York Rep. Alexandria Ocasio-Cortez's bid for Congress last year vowed to oppose former Vice President Joe Biden in the 2020 Democratic presidential primary, blasting him as part of the “old guard” and accusing him of standing in opposition to the “center of energy” in the Democratic Party.

JOE BIDEN OFFICIALLY LAUNCHES 2020 PRESIDENTIAL BID

“While we're going to support the Democratic nominee, we can't let a so-called 'centrist' like Joe Biden divide the Democratic Party and turn it into the party of 'No, we can’t,’” the group Justice Democrats said Thursday.

Biden announced his candidacy for president Thursday. He enters a crowded field of Democratic contenders aiming to unseat President Trump -- nearly 32 years after he announced his first campaign for president. The campaign is Biden’s third bid for the White House, having also unsuccessfully run in 1988 and 2008.

“The old guard of the Democratic Party failed to stop Trump, and they can’t be counted on to lead the fight against his divide-and-conquer politics today,” Justice Democrats said. “The party needs new leadership with a bold vision capable of energizing voters in the Democratic base who stayed home in 2016.”

The group added: “Joe Biden stands in near complete opposition to where the center of energy is in the Democratic Party today.”

BIDEN'S SENATE RECORDS HELD BY HIS ALMA MATER WON'T BE RELEASED UNTIL LATE 2019, POSSIBLY EVEN LATER

Others, though, took issue with the group's claim about the energy in the party.

"It's probably worth noting that while this group, Justice Democrats, calls Biden 'out-of-touch' with the 'center of energy' in the Democratic Party, only 26 of the 79 candidates it endorsed last year won their primaries, and only 7 of those went on to win the general election," said Nate Silver, the editor of FiveThirtyEight.

According to its website, Justice Democrats says its mission is “to elect a new type of Democratic majority in Congress, one which will create a thriving economy and democracy that works for the people, not big money interests.”

“Democrats are increasingly uniting around progressive populist policies like 'Medicare-for-All,' a Green New Deal, free college, rejecting corporate money, ending mass incarceration and deportation. We don’t need someone who voted for the Iraq War, for mass incarceration, and for the Bankruptcy Reform Act while voting against gay marriage, reproductive rights, and school desegregation,” Justice Democrats said Thursday.

The attacks could foreshadow the looming clash between the progressive and establishment wings of the party: Biden, along with independent Sen. Bernie Sanders of Vermont -- who enjoys the support of Democratic Socialists in the party -- have consistently topped the polls in the race for the Democratic nomination.

Fox News’ Lillian LeCroy and Paul Steinhauser contributed to this report.