“It’s kind of a work in progress, but I’m pretty confident there will be substantial Congressional Hispanic Caucus support for the vice president over the course of the next month,” said Rep. Filemon Vela (D-Texas), who, along with Reps. Vicente Gonzalez (D-Texas) and Lou Correa (D-Calif.), is leading the effort to rally the CHC behind Biden.

Biden and California Sen. Kamala Harris currently lead the Democratic primary field in CHC endorsements with three apiece.

“I know for a fact that if Biden doesn’t get elected in the primary next year, we’re gonna have Trump as a president again,” said Gonzalez, who switched his endorsement earlier this month from Julián Castro to Biden.

In recent weeks, “a few” members have quietly lobbied Joaquin Castro to persuade his brother to drop out of the presidential race and run for Senate in Texas, according to Vela.

But members who have spoken to Joaquin Castro say he told them his brother is staying in the race.

Joaquin Castro’s congressional office did not respond to a request for comment, nor did Julián Castro’s presidential campaign.

“There would be overwhelming support for Julián were he to move towards a Senate run,” Vela said. “And when I say that, not only overwhelming support amongst members of the Hispanic Caucus but amongst probably all of the other presidential candidates, and a lot of our energies would be directed toward ensuring he won the Senate primary and the general election in November as a U.S. Senate candidate.”

Gonzalez has also floated Castro, the former San Antonio mayor and Housing and Urban Development secretary, as a strong candidate for Texas governor in 2022.

While Biden was among the last candidates to officially enter the race, he was the first candidate to seek out a meeting with the group, CHC members say. California Sen. Kamala Harris has also requested a meeting but has yet to meet with the caucus, members said.

“He was the first one that really made the effort to come and speak to the Congressional Hispanic Caucus to address our concerns and look for support, and he was way out there early. And I think that was important,” Correa said.

In the meeting with the group, Biden made his case for why he’s the candidate best positioned to defeat Trump next November. He also took questions and pledged to pursue immigration reform, one of the Hispanic Caucus’s top issues.

“Candidates have said that to us over and over again,” Correa said. “But the real issue isn’t will you commit to helping us on immigration or will you help us do this, but rather will you expend the political capital, will you put your shoulder into this one and make sure that we can get this done?”

Correa said Biden gave his word to the caucus that he would.

Most caucus members have remained on the sidelines this year because of the complicated primary politics. Aside from goodwill toward Castro, many had local concerns to consider: Nearly three-quarters of CHC members are concentrated in four states — California, Texas, New Jersey and New York — and each of those states has or had at least one candidate in the 2020 hunt.

As a result, many of those who have endorsed — roughly a third of the caucus — have tended to support home-state hopefuls. Sen. Cory Booker’s two CHC endorsements, for example, come from fellow New Jersey lawmakers: Sen. Robert Menendez and Rep. Albio Sires. Two of Harris’ three endorsements come from her home state.

Castro’s only supporter now that Gonzalez switched to Biden is his brother Joaquin.

Biden allies suggest it’s only a matter of time before some members who remained loyal to home-state candidates come out publicly for the former vice president.

“We’re very lucky to have the support that we have now,” said a Biden campaign official. “But that’s just the beginning. There’s a significant effort underway to get more support, and we expect to see that fairly soon.”

The Castro brothers, for their part, have not pressed hard within the CHC for endorsements.

“I haven’t had any, like, strong-arming or, ‘Please support my brother’” from Joaquin Castro, said one member who requested anonymity to speak candidly. “Nothing like that. I think generally speaking, he’s been very respectful of members who’ve already chosen a candidate.”

But Julián’s failure to take off, nine months after announcing his bid, has left many anxious to choose sides.

“They’re staying loyal. It’s just a matter of what’s the breaking point,” Vela said. “But it’s very clear to me that with respect to members who are [supporting their state’s candidate], the vice president is by far the next choice of most of these members.”

Biden, however, is not a universal choice. Asked about the effort inside the Hispanic Caucus to get members to coalesce around his candidacy, Rep. Chuy Garcia (D-Ill.) said, “Some of us are kind of concerned” about the early push to support the former vice president.

Garcia said it would be tough for all 38 members to rally behind a single candidate. But he acknowledged that “it means something” if a group of members can organize in favor of a candidate.

Garcia, who endorsed Vermont Sen. Bernie Sanders in 2016, said he’s still weighing his options for 2020 but might be ready to endorse someone after the October debate. A dozen candidates have qualified for the stage.

“Personally, I’m wanting him to be impactful, to shine,” Garcia said of Castro. “In the times we live in with this administration in place, I think it’s especially important that someone who is of Latino heritage do well.”

Rep. Adriano Espaillat (D-N.Y.) acknowledged that “there’s a natural inclination to support” Castro given that he’s the single Latino candidate. He noted Castro was the only candidate to speak at the Congressional Hispanic Caucus Institute’s annual gala earlier this month.

But Espaillat is still weighing his options — he has met with several candidates, including Biden; Sanders; South Bend, Ind., Mayor Pete Buttigieg; and Sen. Elizabeth Warren.

While Julián Castro has shined in some debate moments, his tough criticism of Biden since this month’s debate appears to have rubbed many Democrats — including some in the CHC — the wrong way.

“During the last debate when he took a couple of shots at Biden, I think that hurt him more than helped him. And I’ve heard that from a number of sources,” Correa said. “And I’m not gonna mention who, but a lot of people felt that Mr. Castro I think hit a little bit below the belt with some of his comments.”

More important are widespread concerns that, deep into the primary calendar, Castro is not getting enough traction.

“I want to see him in as long as possible,” said Rep. Jimmy Gomez (D-Calif.), who hasn’t endorsed a candidate yet. “Having Julián in the race to add the perspective from the community is vital to remind people that Latinos come from all different backgrounds.”

But Gomez added that he’s keeping an eye on the electability and viability of the candidates — particularly with regard to fundraising.

“I wish Julián had more resources to put a more robust campaign structure and I think he’s trying to stay in the game, but he has a tough hill to climb,” he said.

Castro warned supporters last week that he won’t be able to stay in the race if he doesn’t qualify for November’s debate.

“I don’t say this lightly,” he wrote in a fundraising email Thursday. “If I don’t make the next debate stage, it will be the end of my campaign.”