In the arc of Rep. John D. Dingell ’s storied legislative career, it is easy to discern the fading trajectory of power in Washington over the past six decades.

He was the last of the true committee barons, one who muscled for legislative turf and who had been known to pound his gavel so hard it shattered.

But this is a city where no one seems to have the clout to make things happen anymore, and where even the most junior members of Congress have the ability to stop those who try.

Which is why it is no longer John Dingell’s Washington. And why he has decided to hang it up when his term ends.

Dingell is still up to the job, he insisted, though he is a frail 87 years old. The problem, he said, is Congress itself.

“I find serving in the House to be obnoxious,” he told the Detroit News , which on Monday broke the story that Dingell plans to retire. “It’s become very hard because of the acrimony and bitterness, both in Congress and in the streets.”

“Is it fixable?” Dingell said in an interview with The Washington Post. “There’s only one person that can fix it, and there’s only one group of people that can answer that question, and that’s the voters. If they want it to change, it will change.”

Having served 59 years — longer than anyone in the history of Congress — Dingell (D-Mich.) left his imprint on legislation that ranged from the establishment of Medicare to environmental laws to civil rights legislation.

In the 1980s, the prospect of a subpoena from his headline-
grabbing investigative subcommittee was so terrifying that some Washington law firms built a specialty practice that the newspaper American Lawyer dubbed “the Dingell bar.”

Dingell’s is the latest in a series of high-profile departures from the House, marking both a generational shift and the vanishing of a breed of master lawmakers.

Among those who have also recently announced that they will not seek reelection is his longtime adversary Henry A. Waxman (D-Calif.) , who in 2008 unseated him as chairman of the Energy and Commerce Committee.

Dingell was shoved aside because a new wave of liberal, activist lawmakers, elected in 2006 and 2008, viewed him as an obstacle to climate-change legislation and other measures that he opposed on behalf of his constituents — and the industries that employ them — in the industrial Midwest.

He also found himself increasingly out of step with many of his Democratic colleagues in other ­areas, including gun control. ­Dingell was once a National Rifle Association board member.

Yet on other issues, Dingell is an ardently old-style liberal. His most cherished cause was expanding health care coverage, which came to fruition with the passage of the Affordable Care Act.

For decades, at the start of each congressional session, Dingell would introduce national health insurance legislation nearly identical to a bill that his father and con­gressional predecessor, Rep. John ­Dingell Sr., first offered in 1943.

The younger Dingell won election to the House after his father’s death in 1955; between them, father and son had represented their Michigan congressional district since the start of the New Deal in 1933.

Last June, Dingell surpassed the record of the late Sen. Robert C. Byrd (D-W.Va.) to become the longest-serving member of Congress ever.

And Dingell’s retirement may not mean the end of the family dynasty. His wife, Deborah, an executive and a powerful force in Democratic circles, is considering a run for the seat; she would be a favorite if she does. The district leans heavily Democratic; President Obama beat GOP nominee Mitt Romney there by 34 points in 2012.

Asked about his wife’s plans, Dingell said: “She is the one who is going to make that decision. She has not told me what she’s planning on doing. She is making up her mind at this time. . . . To be very truthful with you, I think she’d be one hell of a good congresswoman. She’s able and decent and smart and tough as hell.”

Deborah Dingell did not respond to a request for comment.

John Dingell Jr. came to Congress in an era when committee chairmen ranked as the House’s real powers, with clout that exceeded even that of the speaker.

He became known as Big John and “The Truck” — nicknames that described both his 6-foot-3 stature and the force with which he was willing to exert his will.

When Dingell took the helm of the Energy and Commerce Committee in 1981, he embarked on a campaign of empire building, extending its turf, often over the protests of other lawmakers. Its jurisdiction became the broadest of any panel in Congress, including not only energy but also health, the environment, telecommunications and consumer protection.

The National Journal once described the committee’s purview as “anything that moves, burns or is sold.”

Dingell also kept his committee members in line. When Rep. James Florio (D-N.J.), later New Jersey’s governor, persisted in battling for tougher Superfund waste-cleanup laws in the subcommittee that he chaired, Dingell simply abolished the subcommittee.

Starting in the 1990s, however, power among House Democrats began shifting toward those who represented the liberal coasts — among them, Rep. Nancy Pelosi (Calif.).

Her rivalry with Dingell was such that when redistricting forced him into a primary race against another incumbent Democrat in 2002, Pelosi backed his opponent, Rep. Lynn Rivers. ­Dingell, however, won handily.

But the committee system from which he derived his power was fraying, as clout and leverage moved into the suites of the House speaker and the Senate majority leader. And even they now lack the ability to control unruly junior members, whose allegiance is bound more to ideology than party discipline.

Dingell is the Democrats’ third former House committee chairman to announce his retirement plans in the first two months of the year, following Waxman and Rep. George Miller (D-Calif.). Another, Rep. Collin C. Peterson (D-Minn.), is still considering whether to run again.

On the Senate side of the Capitol, five committee chairmen decided not to run for reelection in November, taking with them a combined 150 years of senatorial experience.

Each has his reasons for retiring, and almost all are in their 70s or 80s, but their collective departures suggest that the committee system has eroded to near-irrelevance. Almost no major legislation follows the how-a-bill-becomes-a-law path that students used to learn in their social studies classes.

And, as Dingell pointed out in a speech in Michigan on Monday, not much is being accomplished.

“This Congress has been a great disappointment to everyone — members, media, citizens and our country,” he said. “Little has been done in this Congress, with 57 bills passed into law. That is not Heinz packaged varieties, it is the laws passed by the Congress.”

Alice Crites contributed to this report.