Hill.TV host Krystal Ball weighed in Tuesday on the escalating feud between Sens. Elizabeth Warren Elizabeth WarrenWarren, Schumer introduce plan for next president to cancel ,000 in student debt The Hill's 12:30 Report - Presented by Facebook - Don't expect a government check anytime soon No new taxes for the ultra rich — fix bad tax policy instead MORE (D-Mass.) and Bernie Sanders Bernie SandersMcConnell accuses Democrats of sowing division by 'downplaying progress' on election security The Hill's Campaign Report: Arizona shifts towards Biden | Biden prepares for drive-in town hall | New Biden ad targets Latino voters Why Democrats must confront extreme left wing incitement to violence MORE (I-Vt.) over whether a woman could win the White House.

Ball, a vocal Sanders supporter, accused Warren of playing the “sexist card” and embellishing the Vermont senator’s comments during a private meeting in 2018.

“This is one of the nastiest political attacks I have seen — certainly the nastiest of this cycle,” Ball said on air.

She argued that Warren’s remarks from the previous day would only hurt her campaign in the long run.

“What started as a potential crisis for Bernie ended in an outrageous meltdown for Warren — a messy flap that is only likely to get messier and worse for Warren tonight,” Ball said. “So much for unity.”

Her comments came a day after Warren issued a statement saying Sanders had told her that he believes a woman could not win the presidency.

“Bernie and I met for more than two hours in December 2018 to discuss the 2020 election, our past work together and our shared goals: beating Donald Trump Donald John TrumpHR McMaster says president's policy to withdraw troops from Afghanistan is 'unwise' Cast of 'Parks and Rec' reunite for virtual town hall to address Wisconsin voters Biden says Trump should step down over coronavirus response MORE, taking back our government from the wealthy and well-connected, and building an economy that works for everyone,” Warren said. “Among the topics that came up was what would happen if Democrats nominated a female candidate. I thought a woman could win; he disagreed.”

The statement was released in response to a CNN report Monday citing four anonymous sources close to Warren who said Sanders made the remarks.

Sanders blasted the CNN report before Warren issued her statement.

"It is ludicrous to believe that at the same meeting where Elizabeth Warren told me she was going to run for president, I would tell her that a woman couldn't win," Sanders said.

Several progressive commentators have since come to Sanders’s defense, resurfacing a video of him in 1988 proclaiming that a woman “could be elected president.”

The feud marks an escalation between the two progressive heavyweights, as Sanders surges in the polls. Over the weekend, Warren said she was “disappointed” to hear that Sanders was urging volunteers to “trash” her campaign. The Sanders campaign denied her characterization.