Sen. Mitch McConnell, R-Ky., is expected to set the all-time record for longest-serving Senate leader Tuesday, even as his counterpart in the House struggles secure the speakership.

McConnell plans to deliver a floor speech acknowledging the new record Tuesday afternoon. He will surpass the late Sen. Mike Mansfield, D-Mont. McConnell has served in the GOP Senate leadership since 2007.

"Designated party floor leaders have been a feature of the Senate for more than a hundred years. And no two have done the job exactly alike," McConnell is expected to say during his speech, according to Punchbowl News. 

"There’ve been leaders who rose to the job through lower-key, behind-the-scenes styles; who preferred to focus on serving their colleagues rather than dominating them. And that … is how Senator Michael Joseph Mansfield of Montana became the longest-serving Senate leader in American history until this morning," he will add.

McConnell easily fended off a challenge from Sen. Rick Scott, R-Fla., last year to maintain his position as leader. Meanwhile, Rep. Kevin McCarthy, R-Calif., is facing an uphill battle to secure the votes he needs to win the speakership on Tuesday.