Senator Mitch McConnell of Kentucky, the minority leader, was hospitalized on Wednesday night after tripping at a hotel in Washington, D.C., his spokesman said.
“This evening, Leader McConnell tripped at a local hotel during a private dinner,” the spokesman, David Popp, said in a brief statement early Thursday morning. “He has been admitted to the hospital where he is receiving treatment.”
No details were immediately available about the 81-year-old Republican’s condition. In 2019, Mr. McConnell underwent surgery after fracturing his shoulder on a patio at his home in Louisville.
Before the accident on Wednesday, Mr. McConnell had been at the Capitol well into the evening, helping to secure a victory for Republicans: an overwhelming Senate vote to overturn a new District of Columbia criminal code that reduces mandatory minimum sentences for some violent offenses.
The vote sent the measure to President Biden’s desk. Mr. Biden had initially opposed the legislation, but he abruptly changed course last week by saying he would sign it, a move that Mr. McConnell described on Wednesday as “flip-flopping.”
It was unclear on Thursday whether the accident would keep Mr. McConnell away from the Senate, where Democrats have a slim, 51-49 majority.
Senator John Fetterman of Pennsylvania, a first-term Democrat who has worked remotely for weeks while receiving treatment for clinical depression, has been unable to vote because he has not been physically present in the Senate. Last week, the absence of Mr. Fetterman and other Democratic senators forced Vice President Kamala Harris to cast the tiebreaking vote on two of Mr. Biden’s judicial nominations.
Mr. McConnell, the former majority leader, is the longest-serving Senate Republican leader in history. Last year, he overwhelmingly won re-election as the party’s Senate leader, holding off Senator Rick Scott of Florida in the first challenge he had faced since assuming the Republican leadership post in 2007.
Luke Broadwater contributed reporting.
