President Trump lashed out at Senate Majority Leader Mitch McConnell on Monday night for acknowledging Joe Biden won the election, sending a slide to Republican lawmakers taking credit for saving McConnell's career with a tweet and robocall.

Why it matters: It's an extraordinary broadside against McConnell by the sitting president and most popular Republican in the party, ahead of a crucial runoff election in Georgia on Jan. 5 that will determine control of the Senate.

• "Sadly, Mitch forgot,” reads the top of the slide sent to Republican senators by Trump's personal assistant, written in red for emphasis. “He was the first one off the ship.”

Between the lines: While both the message and its delivery targeted McConnell, they also carried a subtle warning to other Republicans who may follow suit as the president grasps at the last straws of his election-fraud claim.

• Trump’s remaining power over the GOP is not his waning authority as president, but the perception of his lingering ability to make or break politicians in their re-election campaigns.
• Many Republicans have been loath to criticize the president despite a string of court losses, including at the Supreme Court, because of their private fears that an enraged Trump will attack them and turn his band of loyal followers against them in a primary campaign.

In the case of McConnell, who survived a $93 million onslaught from veteran and Democratic challenger Amy McGrath, Trump’s slide points to polling that showed the Kentucky race in a dead heat until June 19, when the president sent a tweet endorsing the Senate leader.

• The slide shows polling tightening again to 51%-40% before an Oct. 31 Trump robocall. McConnell's final margin of victory over McGrath was 57.8%-38.2%.
• Notably, McConnell's wife Elaine Chao still serves in Trump's Cabinet as transportation secretary.