A prominent Hillary Clinton staffer-turned-Democratic strategist unleased a vulgar attack on “that a--hole” Sen. Bernie Sanders, I-Vt., for defending fellow 2020 candidate Tulsi Gabbard after Clinton suggested the Hawaii congresswoman is a Russian asset.

“Tulsi Gabbard has put her life on the line to defend this country. People can disagree on issues, but it is outrageous for anyone to suggest that Tulsi is a foreign asset,” Sanders tweeted on Monday.

Adam Parkhomenko, a former Hillary Clinton staffer who bills himself as “one of the Democratic Party’s top grassroots organizers,” attacked Sanders for the tweet.

2020 DEMS DISMISS HILLARY CLINTON'S ATTACKS, RALLY TO TULSI GABBARD'S DEFENSE OVER RUSSIA ACCUSATION

“Bernie joins Trump and thousands of Russian bots in defending the person who blamed the US instead of Assad for gassing his own people. Not to mention his not so stellar voting record on Russian sanctions,” Parkhomenko wrote to his nearly 300,000 followers.

“F--k Bernie. I’d forgotten how much I despise that a--hole. Thanks for the reminder,” Parkhomenko added.

Someone responded to the foul-mouthed Parkhomenko, asking him how the rhetoric is productive.

HILLARY CLINTON FLOATS CONSPIRACY THAT TULSI GABBARD IS BEING 'GROOMED' BY RUSSIANS

“Yeah, let’s wait and talk about it next October. Or maybe we listen to the lady who was right about all of this s--- in ’16,” Parkhomenko shot back. “Sticking together is not s---ting on Hillary and ignoring her warnings.”

Parkhomenko is considered a Clinton superfan and The Washington Post ran a 2018 feature about Parkhomenko headlined, “Meet the Clinton staffer who has devoted his life to her cause. Will it be worth it?”

“[The Clinton] campaign knows it can trust Parkhomenko. They know he has dedicated much of his life, since age 17, to her ascent to the presidency. They know he put off college to work for her, then started the Ready for Hillary super PAC,” the Post wrote. “His fanaticism is a very practical kind. You might even call it . . . Clintonian.”

Adam Parkhomenko was a prominent fundraiser for Hillary Clinton during her failed 2016 presidential campaign. (Paul J. Richards/AFP/Getty Images)

Appearing on former President Obama aide David Plouffe’s “Campaign HQ” podcast, Clinton did not mention Gabbard specifically by name, though Plouffe ended the podcast by noting Clinton’s “belief that Tulsi Gabbard is going to be a third-party candidate propped up by Trump and the Russians.”

“I'm not making any predictions but I think they've got their eye on somebody who is currently in the Democratic primary and are grooming her to be the third-party candidate,” Clinton said, in an apparent reference to Gabbard. “She's the favorite of the Russians. They have a bunch of sites and bots and other ways of supporting her so far.”

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Clinton’s podcast performance prompted Gabbard to respond forcefully on Twitter, calling her the “queen of warmongers, embodiment of corruption and personification of the rot that has sickened the Democratic Party.”

An increasing number of other 2020 Democratic candidates have also positioned themselves in Gabbard's camp, rejecting Clinton's claims, defending Gabbard and attempting to shift the conversation to other topics. Gabbard herself posted a video message over the weekend claiming Clinton’s accusation was simply payback for her defiance of the party establishment during the 2016 presidential election.

Parkhomenko is the president of the Renegade Group and co-founder of TRR Group, according to his personal website. He worked for Clinton during her failed 2016 campaign.

Fox News’ Brooke Singman and Alex Pappas contributed to this report.