The list of congressional Republicans calling it quits keeps growing.

This week, Rep. Trey Gowdy (R-SC), who chairs the House Oversight Committee, announced he will be leaving politics to return to the justice system at the end of this year. “I enjoy our justice system more than our political system,” Gowdy said in a statement.

New Jersey Rep. Rodney Frelinghuysen, who leads the Appropriations Committee, a highly coveted position, also announced his retirement this week, with four years left in his chairmanship. Twenty-one House Republicans have announced retirement this Congress, and a host of others are leaving to seek different political office or have already resigned.

Each departure has come with its own personal story. Some, like California Reps. Darrell Issa and Ed Royce, are from swing districts; others are avoiding political fallout from scandal, like Rep. Joe Barton (R-TX).

But there are some overarching trends worth mentioning: Congressional leadership has increasingly centralized decision-making away from individual lawmakers, and there’s a growing understanding that House Republicans could slip into the minority after this midterm election cycle. Paired together, lawmakers are likely asking themselves the point of being in the Capitol, said Jason Roberts, a political scientist at the University of North Carolina Chapel Hill who studies Congress.

It’s a reality Gowdy has lamented for years, telling writer Marin Cogan in 2011, “Do I think I’m making a difference? No. Not from a legislative standpoint.”

Is being a representative just a really shitty job that’s getting worse?

Most of the congressional retirement announcements have come with a feeling of frustration; an admission that perhaps being in the House of Representatives lacks the influence that most associate with the country’s power center.

“I originally announced I was leaving because I thought I could do more in the governor’s seat, but today I believe actually I could do much more for the country by running for Senate,” Rep. Jim Renacci (R-OH), who appears to have adopted an anywhere-but-here view of his career in public service, told Vox.

Another, Rep. Pat Tiberi (R-OH), a high-ranking member on Ways and Means Committee — still considered a highly desirable position — resigned from his congressional post this year to take an executive position with a business group in his home state. Rep. Ileana Ros-Lehtinen (R-FL), who sits in an increasingly Democratic district, attributed her early decision to retire in part to a level of partisanship and gridlock that she said is a “detriment to civility and of good government.”

There’s a tacit understanding that if lawmakers were polled for job satisfaction, the results would be pretty bleak, Roberts said.

James Wallner, who’s now a political scientist with the conservative R Street think tank and served a legislative director under Jeff Sessions and Sen. Pat Toomey (R-PA) and former executive director of the Senate Steering Committee under Toomey and Sen. Mike Lee (R-UT), can personally attest to this.

“When I was there, it was a miserable environment,” Wallner said of both the House and the Senate. “The sense of powerlessness was pervasive — everyone feels powerless including the leaders.”

It’s only gotten worse. With only a slim margin of power, a deepening partisan divide between Republicans and Democrats, an ideological rift within the Republican Party, and an extraordinarily unpopular Republican president in Donald Trump — who has an apparent lack of policy knowledge — lawmakers have been left with a lot of “sitting around waiting,” Wallner said.

“These members didn’t sign up to come to DC to legislate peanuts.”

House Speaker Paul Ryan.

Mark Wilson/Getty Images

Three key factors help create this sense of powerlessness

Perhaps the retirement most telling of a shifting political dynamic in Congress is Frelinghuysen’s.

As chair of the Appropriations Committee, the New Jersey Republican sits in a position that lawmakers work their entire careers to reach. And unlike many of the other lawmakers who are retiring at the end of their chairmanships, Frelinghuysen will walk away in the middle of his six-year term.

Conversations with outside observers, lawmakers, and political scientists point to three main factors that could be influencing this decision.

1) In today’s Congress, decisions are made by leadership, leaving committees to atrophy

There’s no question that committees, much like “regular order,” have less of a role in today’s Senate on high-priority legislation. Committee chairs’ roles have diminished, and power has centralized in the leadership offices.

It’s been a long time in the making. Since the 1990s, committee chairs have been subject to six-year term limits — an effort to rein in the power of individual chairs. But in keeping these high-ranking lawmakers accountable to party leadership, the shift has contributed to the current GOP “paralysis,” Politico’s John Bresnahan writes:

Ryan and John Boehner have been hobbled by deep ideological divides within their own party. ... Before cutting any deal with Democrats, top Republicans must account for whether the Freedom Caucus or some other group will try to oust the speaker. Being ideologically pure is more important than being effective. All of which leads to the worst possible outcome for the House: weak speakers overseeing weak committee chairmen. It’s a perfect prescription for inaction and dysfunction.

Being chair once meant you were in the cool kids’ club, and assignments on powerful committees meant a say in major legislation debates. Now there is less opportunity to participate, let alone dictate the agenda.

“Members are less invested in the process,” Roberts said. “They often don’t feel committed to the product that comes out. That leads into the ‘why am I here? I’m not doing anything — what’s the point of being here?’”

2) Banning earmarks means lawmakers don’t even have the little victories to take home anymore

The decline of the committees’ power is no more apparent than with appropriators — the group of lawmakers in control of the nation’s purse strings.

Once, not long ago, when it came to negotiating spending bills, lawmakers would start lining up around Appropriations Committee members — dubbed “cardinals” — on the House and Senate floor to win cash carveouts for special projects in their districts, called earmarks. The practice was banned in 2011 after Republicans argued it led to unnecessary spending and bred corruption.

The effect of banning earmarks, however, had serious consequences for members and committee chairs. It’s not lost on many Republicans that the past legislative year, jammed with difficult partisan votes on health care and a tax overhaul, could have been made easier if members were then able to go home with millions of dollars for a desperately needed infrastructure project.

It comes up “more often than you might realize,” said Rep. Ryan Costello (R-PA), who sits in a vulnerable suburban seat.

Most likely, this could have given someone like Frelinghuysen, who is from a moderate Republican district and whose constituents had to swallow some difficult tax hikes from the SALT repeal, some political cover. Frelinghuysen voted against the tax bill.

3) If this is what being in control of both chambers and the White House looks like, it’s hard to expect a better future for Republicans

In the first year of controlling both chambers of Congress and the White House, Republicans have been either mired in political infighting and inaction or forced into difficult votes. As New America senior fellow Lee Drutman writes:

Because party leadership centrally plans so much of what happens in Congress, members have no ability to exercise any independent policymaking capacity. Divisive polarization means constant gridlock and a Congress whose main legislative activity is voting on whether to keep the government funded every few weeks. Hardly rewarding work.

Now going into the midterm elections, the electoral impact of Trump’s unprecedented unpopularity is not lost on Republican House members.

“I think everybody is aware of what the environment is because they deal with Indivisible people outside their office every week protesting,” Costello, whose district surrounds Philadelphia and who is being targeted by Democrats, said. “I know that I do. There has been more intensity.”

2017 was a rare chance for Republicans to govern, and now there’s a growing possibility that power could slip away.

“If you can expect things will get better, that can carry you far,” Wallner said, explaining why Democrats seem more intent on staying in Congress. “For Republicans now, there is nothing left to expect.”

Being in the minority in the House is a lot worse

Being in the minority is always worse.

Toni L. Sandys/The Washington Post via Getty Images

Taking back control of the House won’t be an easy task for Democrats, but they are already claiming to have momentum on their side. There’s some clear evidence to that effect: State elections in Virginia and Wisconsin have resulted in shocking upsets for Republicans, and special elections to fill once deeply conservative congressional seats — like in South Carolina and Georgia — have become more difficult contests.

These retirements signal a notable upheaval in the Republican Party, and the departures only further reinforce the trend by opening up more seats for Democrats to be competitive in.

“These are the canaries in the coal mine,” Roberts said. “Republicans are starting to envision a world where they will lose their majority.”

And as difficult of a year it has been for Republicans while in the majority, it will be even worse in the minority.

“This midterm is going to be a referendum on the Republican Party and, specifically, the president of the United States and his conduct in office,” said Rep. Charlie Dent (R-PA). Dent, a moderate Republican who announced his retirement last year, has cited Trump as one factor in his decision.

For many, perhaps, the understanding is that the referendum won’t turn out in Republicans’ favor.