Julian Castro, who ran against President Biden for the 2020 Democrat presidential nomination, warned of a "softness" around the president’s "electability" come 2024.

In a Monday New York Times article, Castro warned of Biden’s "electability" in the upcoming presidential election, saying he thinks there are some people who don’t believe the president has followed through on his 2020 campaign promises.

"It’s clear there is a softness that perhaps is born out of a worry about electability in 2024," former President Obama’s Housing and Urban Development (HUD) secretary said.

TRUMP’S GOP OPPONENTS TEST OUT DIFFERENT RESPONSES TO HIS INDICTMENT AS THEY JOCKEY FOR POSITION BEHIND HIM

Julian Castro, who ran against President Biden for the 2020 Democrat presidential nomination, warned of a "softness" around the president’s "electability" come 2024. (Getty Images)

"While he’s accomplished a lot, there have been areas where I think people feel like he hasn’t quite delivered what was promised on voting rights, immigration reform, police reform and some aspect of climate," Castro continued.

Castro and Biden frequently butted heads on the campaign trail in 2019, with the former HUD secretary initially endorsing Massachusetts Senator Elizabeth Warren’s ill-fated presidential bid after ending his own in early 2020.

The former HUD secretary eventually did endorse Biden for president — in June 2020, two months after Biden had become the de facto Democrat nominee.

President Joe Biden eats ice cream

Castro and Biden frequently butted heads on the campaign trail in 2019, with the former HUD secretary initially endorsing Massachusetts Senator Elizabeth Warren’s ill-fated presidential bid after ending his own in early 2020. (MANDEL NGAN/AFP via Getty Images)

Castro’s comments come as Biden faces two Democratic primary challengers ahead of 2024.

Democratic presidential candidate Robert F. Kennedy, Jr., came out of the gate with double-digit polling numbers while fellow Democrat candidate Marianne Williamson has been gaining steam, as well.

cheryl hines and robert f. kennedy jr on red carpet

Democratic presidential candidate Robert F. Kennedy, Jr., came out of the gate with double-digit polling numbers while fellow Democrat candidate Marianne Williamson has been gaining steam, as well. (Joshua Blanchard/Getty Images for Waterkeeper Alliance)

The polls have not gotten better for Biden, either, and are a flashing warning sign for the president’s campaign ahead of 2024.

The Democratic National Committee (DNC) said they will not be having primary debates this election cycle, which provides cover for Biden and helps him avoid being challenged by his Democratic opponents. Fox News Digital recently asked multiple House Democrats about whether Biden should debate RFK Jr. in a Democratic primary, prompting them to dismiss this proposal, calling Kennedy a "fringe candidate."

"No," Rep. Glenn Ivey, D-Md., said bluntly when asked whether the Kennedy scion should get to debate the sitting president. "I, you know, love the Kennedy family. I was a huge fan of his father, in fact, he was an inspiration to me. But I don’t think he’s a serious candidate. I think Joe Biden’s going to be our nominee, and he deserves to be."

Marianne Williamson

Self-help author Marianne Williamson speaks to the crowd as she launches her 2024 presidential campaign in Washington, Saturday, March 4, 2023. The 70-year-old onetime spiritual adviser to Oprah Winfrey became the first Democrat to formally challenge President Joe Biden for the 2024 nomination.  (AP Photo/Jose Luis Magana)

CLICK HERE TO GET THE FOX NEWS APP

Rep. Zoe Lofgren, D-Calif., was equally opposed to the idea, saying, "He’s a fringe candidate, so I don’t think Biden is going to necessarily debate fringe candidates. Nor should he."

In a recent Newsweek op-ed, Marianne Williamson said the Democratic Party "must allow President Biden to debate his opponents," blasting the current move as "candidate suppression."

"They believe in the power of democracy; they just don't want to facilitate it. In fact, they're not above thwarting it when it might challenge their own power or lay bare some inconvenient truths about how this country operates," she wrote. "They don't really think the people can be relied upon to make their own decisions about pretty much anything, least of all who should be president of the United States."

Fox News Digital's Paul Steinhauser and Liz Elkind contributed reporting.