In an extraordinary conference call this morning with fellow Senate Republicans, Majority Leader Mitch McConnell said his Jan. 6 vote certifying Joe Biden's victory in the 2020 election will be "the most consequential I have ever cast," according to a source on a call and two other sources briefed on the private remarks.

The big picture: The conference call came in the wake of Sen. Josh Hawley defying McConnell's wishes and publicly declaring that he'll object to certifying the electoral votes in Pennsylvania and perhaps in other states as well.

• McConnell had previously urged senators not to force this vote, which he believed would put Republicans up for re-election in 2022 in a horrible position — forcing them to choose between defying the most popular politician in the party, Donald Trump, and undermining democracy.
• His remarks to his conference are likely to escalate President Trump's anger with him for daring acknowledge Trump's defeat.

Behind the scenes: McConnell said on the call that the January 6th vote is "a vote of conscience," these sources said.

• A source paraphrased McConnell as saying, "I'm finishing 36 years in the Senate and I've cast a lot of big votes." including over war and impeachment.
• "And in my view, just my view," McConnell said, "this is will be the most consequential I have ever cast."
• "The context was McConnell saying we're being asked to overturn the results after a guy didn't get as many electoral votes and lost by 7 million popular votes," the source said.

Between the lines: Many Republican senators are furious at Hawley for forcing them to take what Trump is setting up as the ultimate loyalty test on January 6th.

• On the call, McConnell asked Hawley to explain what he planned to do on a January 6th, said a source on the call.
• Then, Indiana Sen. Todd Young pressed Hawley on which states he planned to contest, and Pennsylvania Sen. Pat Toomey defended the integrity of his state's elections.
• There was just one problem: They were met with silence. Hawley hadn't dialed into the conference call — a fact first reported by Politico's Alex Isenstadt.

What's next: Hawley has no plans to back down from his decision to object to the certification of the electoral votes — a ploy destined to fail on Jan. 6.

• Hawley has been fundraising off of his planned objection to the election results, and this afternoon he emailed his Senate colleagues explaining his reasoning and copy-pasting a public press release he issued the day before to announce his decision.
• In his email to his colleagues, Hawley made clear he was responding to pressures from his constituents.
• "If you've been speaking to folks at home, I'm sure you know how deeply angry and disillusioned many, many people are — and how frustrated that Congress has taken little or no action," he wrote.