McConnell is one of 11 U.S. senators to serve as party leader for over a decade

• McConnell began serving in the Senate in 1985. He was minority leader from 2007 to 2015, majority leader from 2015-2021 and minority leader again from 2021 to the present.
• He has served as Republican party leader for 17 years.
• Seven of the longest-serving leaders were Democrats, and four have been Republicans.

Between the lines: During former President Trump's administration, McConnell confirmed three Supreme Court justices and hundreds of judges. Leading to the 2024 presidential election, McConnell has declined to endorse Trump.

• Three GOP senators are viewed as the most likely to take on the role next.

Zoom out: The five longest-serving senators before McConnell were all Democrats and served terms ranging from 12 to 16 years.

Mike Mansfield (D-Mont.) served in the Senate from 1953 to 1977.

• He was the party leader, as majority leader, from 1961 to 1977.
• He was part of the Marine Corps, and eventually served as U.S. ambassador to Japan.

Joseph Robinson (D-Ark.) served in the Senate from 1913 to 1937.

• He was the party leader, as both majority and minority leader, from 1923 to 1937.

• He was a skilled defense attorney and was considered the "marshal" of President Roosevelt's New Deal.

Robert Byrd (D-W.Va.) served in the Senate from 1959 to 2010.

• He was party leader, as both majority and minority leader, from 1977 to 1989.
• Byrd was also the longest serving senator in history, with 51 years in office.

Here are the other longest-serving party leaders:

• Alben Barkley (D-Ky.): 12 years
• Harry Reid (D-Nev.): 12 years
• Bob Dole (R-Kan.): 11.5 years
• Arthur Gorman (D-Md.): 11 years
• Charles McNary (R-Ore.): 11 years
• Everett Dirksen (R-Ill.): 10 years
• Tom Daschle (D-S.D.): 10 years

Go deeper: McConnell replacement race kicks off earlier than expected