Sen. Bernie Sanders Didn't 'Know How' to Take Being Referred to as an 'Ignorant Sl--' During Hearing

Sen. Bernie Sanders did "not know how" to respond after being pulled into an unusual exchange during the Cabinet confirmation hearing this week for President Joe Biden's pick to head the Office of Management and Budget.

Neera Tanden, whom Biden has nominated to head the office, faced tough questioning this week from both Republican and Democratic lawmakers over her use of social media in recent years.

Tanden, 50, is the president of the liberal advocacy group Center for American Progress and was a senior aide for 2016 Democratic presidential nominee Hillary Clinton, during a campaign that saw Clinton and Sanders at odds in the primary.

Lawmakers questioning Tanden this week highlighted her voluminous history of tweets, including many scathing past statements criticizing members of Congress and commenting on issues of the day.

"You called Sen. Sanders everything but an ignorant slut," Sen. John Kennedy, a Republican, said to Tanden, referencing an old Saturday Night Live skit while criticizing the nominee's use of social media against political rivals.

"That is not true," Tanden, 50, shot back, as Sanders looked on during the exchange.

RELATED: New Footage from the Capitol Insurrection Shows Officer Eugene Goodman Directing Mitt Romney Away from Rioters

"When you said these things, did you mean them?" Kennedy, 69, repeatedly asked the Tanden, before she eventually said she "must have" but that "I really regret them."

Once Sanders, 79, regained control of the hearing, Kennedy quickly clarified: "I want the record to reflect that I did not call Sen. Sanders an ignorant slut."

"I don't know how I should take that, Sen. Kennedy," Sanders replied.

Tanden previously tweeted many crass or sharp-tongued comments about lawmakers and other political figures with whom she disagrees — including Sanders, Sen. Ted Cruz and Senate Minority Leader Mitch McConnell.

According to The New York Times, Sen. Rob Portman, another Republican lawmaker questioning Tanden this week, pointed out old tweets the nominee made calling McConnell "Moscow Mitch" and saying "vampires have more heart than Ted Cruz."

RELATED: Trump's 'Terrible' Defense Team Helped Push One GOP Lawmaker to Change His Mind on Impeachment

Sanders also pressed Tanden for answers over her tweets aimed at the independent Vermont senator and other progressive political operatives.

"There were vicious attacks made against progressives, people who I have worked with, me personally," Sanders told Tanden. "Can you reflect a little bit about some of your decisions and some of the personal statements you have made in recent years?"

Tanden vowed to drop the divisive online rhetoric if confirmed as the next head of the budget office.

"I feel badly about that," she told Sanders. "My approach will be radically different."

Watch: Trump lawyers to rebut impeachment case, bringing verdict closer