Senate Minority Leader Mitch McConnell threatened Tuesday to grind the workings of the notoriously sluggish upper chamber to a complete halt if the Democratic majority attempts to scrap the legislative filibuster, a warning that was met with immediate derision given the Kentucky Republican's elimination of the 60-vote rule for Supreme Court nominees less than four years ago.

In a speech on the Senate floor just hours after he dropped his demand that Democrats commit to leaving the legislative filibuster intact as part of a must-pass organizing resolution, McConnell cautioned that "destroying the filibuster would drain comity and consent from this body to a degree that would be unparalleled in living memory."

 "The filibuster is a Jim Crow relic. It represents everything wrong with Washington. Abolish it."
—Rep. Ilhan Omar

"Taking that plunge would not be some progressive dream. It would be a nightmare. I guarantee it," added McConnell, who said Republicans could obstruct Senate business by denying a quorum, the number of senators required to be present for the chamber to operate.

As Daily Kos political director David Nir pointed out, "if Republican senators refuse to show up for a quorum call, Democrats can direct the Senate's sergeant at arms to arrest them and compel their attendance."

"That's how radical a threat withholding quorum is—you can be arrested for doing so," Nir noted.

The minority leader echoed the message of his floor speech in a tweet Tuesday evening, declaring that nuking the filibuster "would drain the consent and comity out of the institution" and leave the Senate unable to function.

Democratic lawmakers and commentators responded by pointing to McConnell's refusal to allow a vote on former President Barack Obama's Supreme Court nominee and subsequent elimination of the judicial filibuster to confirm right-wing Justice Neil Gorsuch in April of 2017—and clear the way for later confirmation of two additional Trump high court nominees.

"You lost all credibility when you stole a Supreme Court seat," tweeted Rep. Ilhan Omar (D-Minn.). "The filibuster is a Jim Crow relic. It represents everything wrong with Washington. Abolish it."

"By the way," the Minnesota Democrat added, "Senate Democrats represent 41.5 million more Americans than Mitch and his caucus. Blocking needed relief for Americans has nothing to do with 'consent and comity' and everything to do with destroying democracy."

Ari Berman of Mother Jones said it is "truly maddening to hear Mitch McConnell warn of 'nightmare' if Dems abolish filibuster when he already killed it to put three Trump justices on the Supreme Court and confirmed Amy Coney Barrett eight days before an election."

McConnell's threat to gum up the works of the Senate even more than he already has came as the chamber's new Democratic majority began taking steps to advance President Joe Biden's proposed coronavirus relief package through the special budget reconciliation process, a move made necessary by vocal Republican opposition to the new aid measure.

The Washington Post reported late Tuesday that "Democratic leaders in both chambers are tentatively planning to introduce a budget resolution on Monday that could come to a vote later in the week."

"The resolution would instruct committees to write legislation codifying Biden's $1.9 trillion pandemic relief plan," the Post reported. "Under special rules governing the budget resolution, the resolution could pass the Senate with a simple majority vote, and the subsequent Covid-19 relief bill could also pass with a simple majority—even without eliminating the filibuster."

While a coronavirus relief package could clear the Senate with the filibuster intact, former Senate staffer Adam Jentleson said in an interview with The.Ink Tuesday that Democrats "will never be able to use reconciliation to pass things like civil rights, democracy reforms, statehood, gun control, or many climate change solutions" due to rules restricting the kind of legislation that can be passed through the expedited budget process—meaning the urgency of abolishing the archaic 60-vote rule remains.

"Pulling our punches now will mean that we fail to reform our democracy and get climate change under control, for starters," Jentleson said. "Then, when McConnell is back in power, he will chuckle and nuke the filibuster himself the first time it serves his interests."

In a series of tweets Tuesday, Jentleson argued that the minority leader's threat to defend the filibuster by plunging the Senate into chaos "is the worst he can come up with and it's vastly preferable to letting McConnell block Biden's agenda."

"Unintentionally," Jentleson added, "McConnell is revealing how his power relies heavily on the filibuster."