WASHINGTON — Senate Minority Leader Mitch McConnell will step down from the helm of the Republican Conference this year, ending his time as the longest-serving leader in Senate history.

The Kentucky Republican, who has served as GOP leader since 2007, made his announcement in a Senate floor speech Wednesday. An election to replace him as leader will occur in November with his successor taking charge in January.

“One of life’s most underappreciated talents is to know when it’s time to move on to life’s next chapter, so I stand before you today, Mr. President and my colleagues, to say this will be my last term as Republican leader of the Senate,” McConnell said, adding in his address that he had “total clarity and peace about the sunset of my work.”

Majority Leader Chuck Schumer, D-N.Y., with whom he has often sparred, was the first to shake McConnell’s hand on the Senate floor after the Republican finished his speech.

McConnell is regarded by colleagues as an effective political tactician and one of the most influential lawmakers in Washington. With then-President Donald Trump, McConnell helped enact a sweeping $1.5 trillion tax package in 2017 that slashed corporate rates, provided new breaks for private businesses and reorganized the individual tax code.

And he shepherded three conservative Supreme Court nominees — Neil Gorsuch, Brett Kavanaugh and Amy Coney Barrett — through the Senate confirmation process, reshaping the judiciary and American society. That court overturned Roe v. Wade in June 2022, ending the national right to abortion.

“There are some pretty major victories that the two men together accomplished, and neither one of them could have, probably, without the other,” said Sen. Kevin Cramer, R-N.D.

But McConnell’s once formidable influence over the Senate GOP has dimmed over the last year as the conference becomes more aligned with Trump, who has a famously frosty relationship with the Republican leader and recently said he didn’t think he could work with McConnell if he’s re-elected president. Trump and McConnell haven’t spoken in more than three years, hitting a breaking point with the Jan. 6, 2021, attack on the Capitol. But their aides have recently held discussions, including an effort to get McConnell to endorse Trump for re-election.

The Republican conference has recently broken with McConnell on matters like Ukraine aid and a bipartisan border security deal. And his critics had promised he would face a challenge if he sought to run again for the leader position.

The race for a successor is expected to begin immediately with the “three Johns” — Senate Minority Whip John Thune, of South Dakota, the No. 3 Republican Sen. John Barrasso, of Wyoming, and former GOP Whip Sen. John Cornyn, of Texas — widely expected to run for the position.

“I plan to support John,” joked Sen. JD Vance, R-Ohio.

Thune, 63, is the favorite to replace McConnell, given that he’s well regarded by colleagues and the No. 2 GOP leader. But while he endorsed Trump in recent days, Thune has also clashed with the former president and likely GOP 2024 presidential nominee — a fact that could complicate the senator’s bid for the top job.

That could provide an opening for either Barrasso, who is more aligned with Trump, or Cornyn, a former No. 2 leader under McConnell and a prolific fundraiser. None of the three Johns announced their bid on Wednesday, allowing McConnell to have his day.

“It is a remarkable record on longevity, on accomplishments, and we ought to celebrate that record,” Barrasso told NBC News.

Health issues for the 82-year-old McConnell almost certainly played a role in his decision. Last March, he sustained a concussion and fractured a rib when he took a bad fall at a private dinner at a Washington hotel, sidelining him for six weeks.

Then in July, McConnell froze for 19 seconds at a news conference in the Capitol, worrying colleagues who said they had noticed a change in the longtime leader and they believed the fall had taken a toll. He appeared to freeze a second time at a Kentucky event the following month.

In announcing his decision, McConnell also noted the toll on his family following the recent death of his sister-in-law, Angela Chao, in a car accident.

McConnell suggested he would finish out his term as senator, which ends in January 2026. “I’ll finish the job the people of Kentucky hired me to do as well, albeit from a different seat,” he said. “And I’m actually looking forward to that.”