WASHINGTON – Sen. Lamar Alexander, R-Tenn., announced Monday that he would not seek reelection in 2020, a move likely to bring a close to a long political career characterized by his ability to seek consensus and work with politicians from both parties.

His departure from the Senate will further deplete the ranks of Republicans inclined to cooperate with Democrats. Congress has grown increasingly partisan in recent years and during President Trump’s tenure, some Republicans who don’t share Trump’s combative approach have headed for the exits.

Alexander, 78, a former Tennessee governor and U.S. education secretary who twice ran for president, said in an interview that he made up his mind in August while he was fishing in Canada.

The senator said he concluded that his three Senate terms and two as governor were enough. “Everything has to come to an end,” he said.

Alexander has cultivated a reputation for being a traditional Republican senator, voting with Trump much of the time but willing to work with Democrats.

Alexander said he waited until the end of the year before announcing his decision to ensure it was the right one. He called Trump on Sunday and before he could reveal it to the president, Trump talked about him serving another 20 years.