Moderate members of the U.S. House of Representatives are leaving office at twice the rate of their more partisan peers this year, a Reuters analysis found, likely deepening Washington gridlock during President Joe Biden's next two years in office.

The number of incumbent House members retiring or who lost a party nomination contest is at a three-decade high after a once-a-decade redistricting process that eliminated more than a dozen of the country's dwindling number of competitive districts.

Now all 50 states have finished their nominating contests, 13 of Congress's 50 most centrist members - about one in four - did not seek reelection or lost their primary, ensuring they will leave office at year's end. By comparison, only one-eighth of other incumbents will not appear on the Nov. 8 ballot, with the majority running in politically safe districts.

The candidates who take their place won't be known until after the midterm election, when Republicans are favored to win a majority in the House, but in many cases their potential successors show signs of being further from the middle.

One driving factor is gerrymandering, the practice by which lawmakers in states controlled by a single party manipulate redistricting to create politically safe House districts. Another is former President Donald Trump, who worked to push from office Republicans who voted to impeach him following the Jan. 6, 2021, attack on the U.S. Capitol.

"The lack of competitive seats has helped accentuate that trend," said Peter Meijer, a Michigan Republican who voted to impeach Trump and lost his primary to a far-right challenger. "It's really easy from the safety of a deep red or a deep blue seat to cast stones."



The Reuters analysis employed a measure developed by political scientists known as DW-Nominate, which scores every representative's voting record to determine the most moderate members.

The share of moderates heading for the door this year is unusually high. For elections held between 2012 and 2020, only about one in eight moderate incumbents opted not to seek reelection or lost their primaries.

The result could accelerate a decades-long trend that has seen the House grow increasingly polarized, lengthening the odds of bipartisan efforts to address thorny challenges such as shoring up Social Security and Medicare, the welfare programs for seniors that face severe fiscal challenges.

"Politics is going to be more gridlocked," said Doug Spencer, an expert on elections and redistricting at the University of Colorado.

The narrowly Democratic-controlled Congress over the past two years passed a $1 trillion infrastructure bill and its first gun control bill in decades in bipartisan votes. But Democrats also passed a $1.9 trillion COVID relief bill in March 2021 and $430 billion climate and drug pricing bill using a parliamentary maneuver known as reconciliation that let them bypass Republican objections in the Senate.

Whichever party is in control, the Congress that convenes on Jan. 3 will need to make prompt decisions on fiscal matters, including raising the U.S. government's borrowing authority beyond its current $31.4 trillion limit, which it is expected to reach early next year.

Without a debt limit increase, Washington would face a potential default that would shake the global economy.



In interviews, several moderates leaving office said their decisions were motivated by factors including gerrymandering, which has made it less politically valuable to appeal to voters from both major parties.

More than four-fifths of the House's 435 districts as they now stand were won by Biden or Trump by more than 10 percentage points in 2020, making it harder for a lawmaker from the other party to mount a viable campaign. That drove some members of Congress, such as Tennessee Democrat Jim Cooper, to choose not to seek reelection at all.

Tom Suozzi, a moderate Democrat from New York who opted to run for governor rather than seek re-election, said gerrymandering was producing more ideologically radical caucuses.

"The only way to lose the safe seat is to lose the primary," he said. "Republicans pander to the far right, Democrats pander to the far left. And that's why there's very little moderation or compromise available."

Suozzi has been a member of the Problem Solvers Caucus, a bipartisan group of moderate lawmakers. The progressive Democrat running in the race to replace him, Robert Zimmerman, has criticized the group for being too close to Republicans.

Stephanie Murphy, a Florida Democrat and a leading centrist, is retiring from the House at age 43, saying she wants to spend more time with her young children. She said she believes both parties have become less tolerant of dissent.

"The reason, I think, you see more attrition among moderate members is they take incoming from both sides," she said, adding that she faced attacks from both liberal and conservative groups in previous campaigns.

Republican control of the House would create divided government, with Biden's Democrats having a harder time advancing legislation.

The push by Trump-backed candidates echoes the 2010 midterms, when small-government Tea Party activists drove massive Republican gains in Congress while moving the party further to the right.

With Democrat Barack Obama in the White House, the two parties courted fiscal disaster when they nearly allowed the federal government to default on its debt payments, prompting the first-ever downgrade to U.S. sovereign debt and shaking financial markets.

Cheri Bustos, an Illinois Democrat and a leading centrist who is retiring this year, said the Jan. 6 attack only deepened distrust between the parties, with many Democrats unwilling to work with Republicans who voted against certifying Biden's victory based on Trump's false claims of fraud.

"We've got to get something done, and that requires us to work with people who you don't always agree with their votes," she said.

(Reporting by Joseph Ax in New York and by Jason Lange and Richard Cowan in Washington; Editing by Scott Malone and Daniel Wallis)