John D. Dingell, the longest-serving member of Congress in American history, and easily the most overpoweringly influential House chairman of this generation, is calling an end to his own era.  

A complex and cunning Democrat who is in his 59th year of representing the Detroit area and who will turn 88 in July, Dingell announced Monday that he would retire at the end of the year rather than seek a 30th full term. The news floored the Capitol, where almost no one in the workaday population has known life without his presence.  

“Presidents come and presidents go,” President Bill Clinton said in 2005 when the congressman celebrated half a century in office. “John Dingell goes on forever.”  

Dingell earned the lasting nickname “Big John,” and the widespread expectation that his time in public life wasn’t near its end, thanks to much more than unmatched perseverance.  

His imposing 6-foot-3 frame has become stooped in recent years, and he often moves through the Capitol on a motorized scooter with a faux vanity license plate of “The Dean” — the honorary title bestowed on the sitting House member with the longest tenure. But he had been talking in recent days about waging a comeback campaign to reclaim his party’s top seat on the Energy and Commerce Committee , where he exercised unequaled power as chairman for 16 years and was ranking Democrat for a dozen years more.  

Although he was deposed from that post six years ago, and seemed unlikely to get it back , the successes he enjoyed in the previous three decades as a canny legislative playmaker, tenacious oversight inquisitor and vigorous turf warrior has rarely been rivaled in congressional history.  

“One of the most influential legislators of all time,” President Barack Obama said in his tribute Monday.  

The president noted Dingell’s central roles in writing the original Clean Air Act, the Safe Drinking Water Act and the Endangered Species Act, but paid special tribute to the most prominent cause they shared: medical insurance coverage for all. (Dingell presided over the House when it cleared the law creating Medicare in 1965 and sat next to Obama at the health care overhaul signing ceremony in 2010. He had proposed “single payer” universal coverage legislation in every Congress until that point, but professed himself satisfied with the measure enacted.)  

From the outset of his Energy and Commerce chairmanship in 1981, Dingell was known as a legislative strategist and political tactician with the capacity to mold broad bipartisan coalitions to his will — although rarely without a fair amount of bruising. His style was to be collaborative in the early stages of legislative bargaining, then clamp down as inflexible once he’d declared his position was settled. Even his allies viewed him as uncommonly stubborn, vindictive and bullying for someone with so much guaranteed power — and with a self-confidence bordering on arrogance, to boot.  

In short, his loud voice, heavy gavel and strong opinions made him a paragon of the domineering chairman just as that type of Old Bull leader was otherwise nearing extinction.  

And he paired all that with a reputation for ruthless accretion of power, with much of the effort spent amassing and then protecting the broadest committee fiefdom any chairmen had enjoyed in the postwar era. In its heyday, Energy and Commerce had most if not all control over bills shaping energy, environmental, health, telecommunications, transportation, financial services and consumer protection policy.  

Efforts by his colleague to so much as chip away at that jurisdiction were repelled with merciless force and a watchful eye ever after. He once said he’d adopted as his own the aphorism the Corleone family made famous in “The Godfather, Part II”: “Keep your friends close, but your enemies closer.”  

And whatever legislative sway he lacked, he made up for with imperious investigatory zeal that inspired fear in Democratic as well as Republican administrations. With as many as 100 aides working for the Oversight and Investigations Subcommittee he also chaired, Dingell would send a seemingly constant stream of letters demanding explanations and information from agencies big and small. When the answers to these “Dingell-grams” were not fast or thorough enough to suit his needs as chairman, he’d quickly dispatch subpoenas and schedule a hearing.  

The breadth and persistence of these inquiries continued between 1995 and 2006, when he was ranking minority member, prompting President George W. Bush to once describe Dingell to his face as the “biggest pain in the ass” on Capitol Hill.  

Adding to his mystique as a merciless competitor is his collection of stuffed fish and game trophies on the walls of his Rayburn Building office, including that of a 500-pound boar he reportedly felled with only a pistol.  

“He will be remembered as one of the most influential members of Congress not to have served as president,” said Rep. Joe L. Barton of Texas, who was ranking Energy and Commerce Republican during Dingell’s final term as chairman, in 2007 and 2008.  

Dingell’s unsurpassed presence on Capitol Hill is an essential part of his story, in part because it began when he moved into the neighborhood as a small boy. Since his namesake father was a New Dealer elected to represent Detroit in the 1932 Franklin D. Roosevelt landslide, young Dingell was first allowed on the House floor at age 6. He served as a House page at 12 and was in the chamber for FDR’s “Date of Infamy” speech after Pearl Harbor.  

Dingell was an assistant county prosecutor in Dearborn when his father died in 1955 during a routine physical. He secured organized labor’s backing in a 12-person primary and then took 76 percent in the subsequent special election for his dad’s seat. At 29, Dingell was the youngest member of the House. (Roll Call was founded the same year.)  

He became the longest-serving House member ever in February 2009 (surpassing the record Mississippi Democrat Jamie L. Whitten set in the early 1990s) and the longest-tenured member in the history of Congress on June 7, 2013 (surpassing Democratic Sen. Robert C. Byrd of West Virginia, who died in office in 2010).  

That endurance means Dingell has been a member for 27 percent of the time the U.S. Congress has existed and has shaped policy with or without the help of a quarter of all the nation’s presidents.  

He is now in his 20th year as the House dean — during which time, seven out of eight of the current members have begun their time at the Capitol. Such is the nature of Dingell’s career that his successor in the longevity title stands to be one of his former Hill aides — John Conyers Jr. Conyers, of note, says he plans to run for a 21st term in a neighboring Michigan district. The Democrat, now 84, joined Dingell’s staff as legislative aide fresh out of law school in 1958.  

Dingell drew less than 60 percent of the vote in a general election only twice: in 1994 and 2010, the last two times Republicans won control of the House. Instead, his toughest elections were the two times he was forced by redistricting to face other incumbent Democrats in a primary. In a district that was a third African-American, he won in 1964 in part because he’d voted for the Civil Rights Act that year but his opponent, Rep. John Lesinski, had voted no.  

Much tougher was his campaign in 2002 against eight-year veteran Rep. Lynn Rivers. That became an intense fight between the very liberal and not-quite-as-liberal factions of the Democratic caucus — and caused a break between Dingell and Nancy Pelosi that proved a decisive downward turning point for his time as a power player.  

With the backing of Pelosi, then the minority whip, Rivers raised significant sums from environmentalists, gun control advocates and supporters of abortion rights — the three communities in the Democratic base with which Dingell has disagreed most prominently. With the help of National Rifle Association members and the auto industry, Dingell won that intraparty battle with 59 percent. But his rift with Pelosi was never repaired, and soon enough she was positioned to help secure an equally consequential Dingell defeat.  

Because of his uncompromising interest in protecting Michigan’s automobile industry, Dingell has long been at odds on energy and pollution policies with the more liberal members of his caucus — Pelosi and fellow Californian Henry A. Waxman principal among them. After her first term as speaker, in which Pelosi and Dingell clashed publicly on several fronts, she got behind Waxman’s challenge to the venerated seniority system. In 2008, Waxman wrested the gavel away from the dean on a 137-122 vote of all House Democrats.  

It was an outcome Dingell seemed unlikely to reverse now in light of Waxman’s own forthcoming retirement . But that reality played no role in his announcement rationale on Monday, which focused instead on the overall state of legislative affairs.  

“This Congress has been a great disappointment to everyone,” he said. “There will be much blaming and finger pointing back and forth, but the members share fault, much fault; the people share much fault, for encouraging a disregard of our country, our Congress and our governmental system.”