"For people to use Russian talking points to sow division among Americans, that is stupid. So Ronna, go to hell," Brazile said, insisting that Democrats "are not trying to prevent anyone from becoming the nominee" to challenge Trump in November.

"If you have the delegates and win, you will win. This notion that somehow or another Democrats are out there trying to put hurdles or roadblocks before one candidate, that's stupid. I know what's going on," Brazile said.

"They are scared of Democrats coming together to defeat Donald Trump," she continued. "They need to be focusing on what we're focusing on in the Democratic Party. And that is preventing foreign interference in our elections. Stop using Russian talking points, Madam Chairwoman. Period. Stop using it."

Appearing on Fox News earlier Tuesday, McDaniel said she did not anticipate "anybody getting out soon" from the Democratic primary, and predicted the race was "leading towards potentially a brokered convention, which will be rigged against Bernie if those super delegates have their way on that second vote."

McDaniel later responded to Brazile's barb on Twitter, writing: "It's ok, @donnabrazile. I'd be having a bad day too if my party was still hopelessly divided. Talk of a brokered convention and the DNC trying to stop Bernie obviously hit a little close to home."

The back-and-forth between the two women regarding a "rigged" Democratic National Convention in Milwaukee comes at a tense moment in the party's nominating contest.

As voters head to the polls in 14 states for the Super Tuesday primaries, Sanders and his supporters have suggested that senior members of the Democratic establishment are lining up to thwart his progressive candidacy and boost the more moderate Joe Biden, who was endorsed Monday by three former rivals: Pete Buttigieg, Amy Klobuchar and Beto O'Rourke.

Sanders, who is poised to rack up a substantial number of delegates Tuesday, has also broken with the rest of the Democratic field in declaring that the candidate who achieves the plurality of delegates should become the party's nominee. Biden, Mike Bloomberg and Elizabeth Warren, however, have said the nomination should be awarded to the candidate with the majority of delegates, per party rules that Sanders himself advocated for in 2016.

Meanwhile, the president and his allies have been eager to push the theory that Democratic leaders are seeking to steal the nomination from Sanders — reopening old party wounds from the 2016 Democratic National Convention, which was marred by allegations of anti-Sanders bias.