(Bloomberg) -- Republican Mitch McConnell will step down as his party’s leader in the Senate after the November election, setting up a fierce succession battle that will be driven by fealty to Donald Trump. 

McConnell, 82, a fixture in the Senate since 1985 and the chamber’s longest-serving party leader in history, has led Senate Republicans for more than 17 years. But he has fought against Trump’s isolationist policies, putting him increasingly at odds with many Republicans on aid to Ukraine and other matters. 

“Father time remains undefeated. I am no longer the young man sitting in the back,” he said on the Senate floor Wednesday. “It’s time for the next generation of leadership.”

McConnell, who is up for reelection in 2026, does not intend to retire from the Senate at the end of the year. 

“I still have enough gas in my tank to thoroughly disappoint my critics,” he quipped. 

McConnell has been the last serious bulwark within the party against Trump’s animosity toward US international commitments, including in Ukraine.

He spent four months nurturing a bipartisan US border deal to appease conservatives who wanted to tie action on migration to Ukraine aid. But the deal caused friction as Republicans shouted at each other in party lunches and hardliners including Ted Cruz of Texas and Mike Lee of Utah called for new leadership.  

The compromise collapsed in less than 24 hours earlier this month under criticism from Trump. 

Earlier: Waning McConnell Is Last GOP Bulwark Against Trump Isolationism

McConnell and Trump have long had a difficult relationship but the animosity grew after McConnell blamed the former president for the Jan. 6, 2021 insurrection at the US Capitol. 

He has not endorsed Trump in his bid to reclaim the White House but likely candidates to succeed him — John Thune, John Cornyn and John Barrasso — all have. 

President Joe Biden, who worked closely with McConnell on bipartisan deals, said the two have had a “great relationship.” 

“We fight like hell. But he has never, never, never misrepresented anything,” Biden said.

Health Challenges

McConnell has faced health challenges, including a fall and concussion last year and two freezing episodes at news conferences. He is noticeably slower in his movement and his speech. That has accelerated the behind-the-scenes maneuvering by potential successors.

During his tenure, McConnell secured a series of generational wins, including a crucial role in the rightward shift of the judiciary that ended federal abortion rights and spearheaded legislation for numerous tax cuts. 

His power has been underpinned by a political shrewdness that inspired confidence in donors and Senate colleagues, allowing him to fund and build a political machine that helped elect allies. McConnell’s campaign skills were on display again recently, as he logged a recruiting victory: Maryland’s popular former governor, Larry Hogan, announced a run for the Senate.

Senate Majority Leader Chuck Schumer, who has frequently sparred with McConnell, walked into the chamber to shake the Kentucky Republican’s hand after his announcement. 

--With assistance from Jordan Fabian, Erik Wasson and Roxana Tiron.

(Adds Biden comment)

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