Rep. Denny Heck, a member of the influential House Intelligence Committee, announced his retirement Wednesday, the latest in a parade of retirements in both parties this year, with Republicans outpacing Democrats 22-8.

In a Medium post announcing his decision, Heck, D-Wash., cited an increasingly rancorous political environment as having taken a toll on him, including the political rhetoric of President Donald Trump.

"In the spirit of complete openness, part of me is also discouraged. The countless hours I have spent in the investigation of Russian election interference and the impeachment inquiry have rendered my soul weary," Heck said. "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."

But Heck didn't put all the blame on Trump: "As has been observed, however, to some degree he is a symptom and not the cause or at least the only cause. The truth is that civic discourse began degrading before him. At times, it is as though there are no rules or boundaries. Success seems to be measured by how many Twitter followers one has, which are largely gained by saying increasingly outrageous things, the more personal the better. There are simply too many hyperbolic adjectives and too few nouns. Civility is out. Compromise is out. All or nothing is in."

Heck plans to enjoy his retirement by writing at least two books. 

The congressman will be joined by more than two dozen lawmakers in both parties. As the Atlantic notes, "18 GOP House members and four senators are forgoing reelection next year without declaring their candidacy for another office, while just seven Democrats in the House and one in the Senate are retiring outright."

This makes this election cycle the second consecutive one where more Republicans are retiring than Democrats. 

That includes Republicans in swing districts like Rep. Will Hurd, R-Texas, a former CIA officer and African American lawmaker who the GOP had long believed would help the party shore up support among moderates. Hurd announced his retirement during the summer, setting off alarms among some conservative strategists. “It’s a huge loss for the district — it almost can’t be overstated,” Matt Mackowiak, a GOP consultant in Texas, told the New York Times. “He’s been running a marathon like a sprint for seven years.”

In addition to this slew of retirements, a few others made the decision to resign due to scandals. Rep. Katie Hill, D-Calif., resigned when it was revealed she had intimate relations with members of her staff. Rep. Chris Collins, R-New York, resigned shortly before pleading guilty to insider trading.