Big-name members of the Democratic Party have not let up on their concerns about what it would mean for the future of the party if Senator Bernie Sanders (I-VT) becomes the party’s presidential nominee in 2020. The latest came from unsuccessful 2004 Democratic nominee John Kerry, who lost to incumbent president George W. Bush.

Kerry, who has been campaigning for former vice president Joe Biden, was overheard discussing Sanders at a Des Moines hotel, according to a report from NBC News. Kerry was reportedly explaining what might be involved if he were to try and wade into the presidential contest given “the possibility of Bernie Sanders taking down the Democratic Party — down whole.”

An NBC News analyst overheard Kerry question if he was “f*cking deluding” himself for considering the possibility of jumping into the race himself, as doing so would require leaving his position as chairman of Bank of America’s Global Advisory Council. Kerry also reportedly said that venture capitalists could potentially raise millions for him as they’re increasingly aware of the apparent threat Sanders poses to their influence on Democratic politics.

Kerry has refuted the idea that his remarks constituted any serious consideration on his part that he would jump into the 2020 race, telling NBC News Sunday, “This is a complete and total misinterpretation based on overhearing only one side of a phone conversation. A friend who watches too much cable called me wondering whether I’d ever jump into the race late in the game if Democrats were choosing an unelectable nominee. I listed all the reasons I could not possibly do that and would not — and will not under any circumstances — do that.”

“I am absolutely not running for President,” Kerry wrote on Twitter in a tweet replacing an earlier version that had a curse word in it. “Any report otherwise is categorically false. I’ve been proud to campaign with my good friend Joe Biden, who is going to win the nomination, beat [President Donald] Trump, and make an outstanding president.”

While Kerry’s phone call doesn’t seem to indicate that he’s seriously considering jumping into the 2020 race, the nature of the conversation (especially with “a friend who watches too much cable”) speaks to the fears some in the Democratic establishment have about the democratic socialist senator winning the nomination.

Those in the middle are anxious that the party is shifting leftward, with Sanders and some of the first-term congresswomen of color who have backed him — including Alexandria Ocasio-Cortez, Ilhan Omar, and Rashida Tlaib — becoming its new faces.