“There’s a wing of the party that supports other candidates, and that’s what you call a primary contest,” Rep. Peter Welch (D-Vt.), who’s endorsed Sanders and co-chairs his campaign in Vermont, told Newsweek. “I don’t call that a conspiracy. This is totally out-front.”

The six-term congressman’s remarks came on Super Tuesday, following recent discussions by moderate and vulnerable Democrats on Capitol Hill about how to potentially prevent Sanders from clinching the nomination by rallying around someone more moderate, like Biden, in a contested convention.

At a Monday campaign rally in Los Angeles, Sanders echoed prior warnings that the Democratic Party’s establishment wing is working to deny him a victory, as he’s alleged it also did in 2016 in his race against Hillary Clinton for the nomination.

After Biden’s strong performance Saturday in South Carolina, he received a string of congressional endorsements, in addition to support from former rivals Pete Buttigieg and Amy Klobuchar.

“The corporate establishment, the political establishment, you are making them very nervous,” Sanders told rallygoers. “They’re really getting quite upset.”

Going into Super Tuesday, Sanders held a narrow delegate lead over Biden and was poised to perform well, especially in the delegate-rich state of California. His strong performance in the primary race thus far has moderate elected Democrats deeply concerned that a self-described democratic socialist at the top of the ticket could spell trouble for down-ballot candidates.

Welch’s suggestion that Sanders and his surrogates should tamp down the rhetoric about unfair efforts to stop his momentum stood in stark contrast to other supporters who want to see the senator become the nominee.

Progressives, particularly those who’ve backed Sanders, warn that brushing aside the strong support Sanders maintains among his base and not coalescing around him as the front-runner could ultimately divide the party and damage its general election chances.

“For any Democrat to minimize the movement that supports Bernie Sanders and to minimize his candidacy, it will backfire on Democrats,” Rep. Pramila Jayapal (D-Wash.) told Newsweek. She co-chairs the Congressional Progressive Caucus and has endorsed the senator.

“Let’s just look at where we are and not fearmonger about a Bernie Sanders presidency or candidacy,” she added.

Rep. Ro Khanna (D-Calif.), who co-chairs Sanders’ campaign, downplayed the recent wave of congressional endorsements for Biden while focusing on the voters’ support for Sanders.

“We don’t believe this campaign is going to be won in Washington, D.C.,” he told Newsweek. “We believe it’s going to be won addressing the concerns of people around the country.”

Welch argued that the perceived divisions in the party are being overplayed and that differences over policy proposals, such as Medicare for All, were normal in a nomination contest. He also rejected the suggestion by Sanders there is an “establishment” rooting against him.

“There is a contest about how best to beat Donald Trump, but that doesn’t mean that those who disagree with one another are ‘part of the establishment,’” Welch said. “This is really a contest of the direction of the party. But to some extent, the direction of the party has largely been established by the Bernie Sanders agenda since 2016. That’s the irony here.”

This story was updated to include remarks from Rep. Ro Khanna.