Rep. Denny Heck announced Wednesday that he is not running for reelection. The Washington Democrat, a member of the House Intelligence Committee, cited the impeachment investigation as part of the reason for his retirement.

“The countless hours I have spent in the investigation of Russian election interference and the impeachment inquiry have rendered my soul weary,” Heck wrote in a Medium post.

“I will never understand how some of my colleagues, in many ways good people, could ignore or deny the President’s unrelenting attack on a free press, his vicious character assassination of anyone who disagreed with him, and his demonstrably very distant relationship with the truth,” Heck wrote.

Heck, 67, also noted serving in Congress takes a toll since it takes him away from his wife. “At our age, however many ‘good years’ we have left together is not a growing number,” he wrote.

Heck was first elected to represent Washington’s 10th District, which includes Olympia, in 2012. Before coming to Congress, he served in the Washington state House and was a former CEO and broadcaster for TVW, the state’s version of C-SPAN.

The 10th District is likely to stay in Democratic hands. Heck won reelection in 2018 by 23 points, and Hillary Clinton carried the district in 2016 by 11 points. Inside Elections with Nathan L. Gonzales rates the race Solidly Democratic.

Heck served as recruitment chair for the Democratic Congressional Campaign Committee in 2016 and 2018, when Democrats flipped the House. He ran unsuccessfully for DCCC chair earlier this year.

Heck is leaving on a legislative high note. He was instrumental in seeing a bill that would allow banks to work with marijuana businesses clear the House with bipartisan support.

Heck also blew up a deal between House Financial Services Chairman Maxine Waters, D-Calif., and ranking member Patrick T. McHenry, R-N.C., to reauthorize the Export-Import Bank with added restrictions on financing deals with Chinese state-owned enterprises.

Major exporters, like Boeing, and labor groups representing those industries balked, and Heck led the Democratic revolt to the deal, leading to a new bill without the restrictions on China that passed in November.

Jim Saksa contributed to this report.