Former Maryland governor Marvin Mandel looks at supporters after being confirmed to the Board of Regents of the University of Maryland in March 2003. (Gail Burton/Associated Press)

Marvin Mandel, the former governor who dominated Maryland’s political landscape in the 1970s and is remembered not only for modernizing and streamlining the state government but also for a racketeering conviction that was overturned on appeal, as well as a nationally publicized divorce, died Aug. 30, a son said.

Mr. Mandel, 95, had heart ailments and died in St. Mary’s County, the son said.

In January 1969, Mr. Mandel, then speaker of the Maryland House of Delegates, was elected governor by the state legislature to serve the remaining two years of the governorship of Spiro T. Agnew, who resigned to become Richard M. Nixon’s vice president.

Mr. Mandel, a Democrat, became one of the most powerful chief executives in the state’s history, and he easily won reelection to four-year terms in 1970 and 1974.

As a politician, he had risen to power through the ranks of the local Democratic Party in his native Baltimore, and he made his political bones as a party loyalist during 17 years in the state’s House of Delegates.

Former Maryland Governor Marvin Mandel in 1979. (James M. Thresher/The Washington Post)

Gov. Larry Hogan (R) said in a statement that Mr. Mandel was “a truly great leader. . . . I will be forever grateful for the advice, wisdom and stories Governor Mandel has shared with me.” Hogan ordered flags to fly at half-staff in Mr. Mandel’s honor.

It always seemed to be his good fortune or good sense — or both — to be in the right place at the right time. Mr. Mandel joined the House in 1952, taking the place of a Baltimore legislator who quit. He later became chairman of the Baltimore delegation to the General Assembly, then chairman of the House’s powerful Ways and Means Committee.

In 1963, when House Speaker A. Gordon Boone resigned after being indicted in a Maryland savings and loan scandal, Mr. Mandel was once again available and ready to take his place, and the House chose him as its new speaker. And he was ready and available to be governor when Agnew resigned.

In the realm of Maryland politics, Mr. Mandel specialized in the art of the possible. His favorite phrase was, “We’ll work it out.”

In The Washington Post’s Sunday magazine in 1974, reporter Richard M. Cohen wrote that “contradictions litter his history. Labels — either ideological or philosophical — fail to fit, and he rejects them all. He has been for and against the same bill.”

Cohen wrote: “He has occasionally lied, generally told the truth, but mostly says as little as possible. His moves are calculated, without passion.”

Visitors to the governor’s office invariably described a scenario in which a relaxed but attentive Mr. Mandel, feet up on his desk, omnipresent pipe in his mouth or hand, leaned back in his chair and listened without comment to their stories, requests, complaints or proposals. Invariably, they left having bared their souls to the governor but with no clue as to what Mr. Mandel thought.

During his years in the legislature, he had learned the political value of paying attention to detail, and in his head he kept tabs on the strengths and weaknesses, the fears and ambitions, the likes and dislikes of the men and women who served in the General Assembly.

He knew how to use this information to work his will, how and which arms to twist and how tightly. He was skilled but also prudent, and it was said that he would never ask a man to cast a legislative vote that might cost him an election. At the state capitol in Annapolis, it generally took no more than the phrase “Marvin wants it” to get a piece of legislation enacted.

Under Mr. Mandel’s leadership, what had been a chaotic hodgepodge of 238 state agencies was reorganized into 12 ­executive-branch departments. Baltimore’s Friendship Airport was acquired by the state and upgraded into what is now the world-class Baltimore-Washington International Marshall Airport. A transportation department was created to deal with 20th-century travel and commuting issues.

In addition, the state assumed responsibility for school construction, and a school lunch program was enriched. About 22,000 people were restored to Maryland’s Medicaid rolls. Courts were reorganized, and a public defender system was implemented.

A handgun-control law was enacted. Hospital costs were regulated. A state automobile insurance program was created. And during all this, the state held the line on tax increases.

“He was a progressive governor. He was a good governor. He moved the state ahead in terms of public services and prosperity,” said George H. Callcott, professor of history emeritus at the University of Maryland and author of “Maryland and America, 1940 to 1980.”

The scandals

But during the Fourth of July weekend in the summer of 1973, the unraveling began. On July 3, Mr. Mandel had made an appointment for his wife of 32 years, Barbara “Bootsie” Mandel, to see their family doctor, and he had the doctor tell Mrs. Mandel that the governor was leaving her. When she called to ask him to reconsider, he told her it was too late. The media had already been informed.

Over the telephone, his press secretary read her a statement that already had been distributed. “I am separated from Mrs. Mandel. . . . My decision, and the separation, are final and irrevocable, and I will take immediate action to dissolve the marriage. I am in love with another woman, Mrs. Jeanne Dorsey, and I intend to marry her. Mrs. Mandel and I have had numerous discussions about this matter, and she is completely aware of my feelings, of my actions and of my intentions. . . . Mrs. Mandel and I no longer share mutual interests, nor are our lives mutually fulfilling.”

Later that afternoon, Bootsie Mandel got on the telephone herself, calling reporters across Maryland and in Washington. “The governor crawled out of my bed this morning,” she told the media. “He has never slept any place but with me. I think the strain of the job has gotten to him. . . . I don’t know what in the world he’s talking about. I hope the governor will come to his senses.”

Mr. Mandel, said his soon-to-be former wife, “should see a psychiatrist.”

In the meantime, she said, she would be waiting at the governor’s mansion. On a slow-news summer holiday weekend, the national media feasted on the story. It became a running joke in Annapolis that what visitors to the governor’s mansion most wanted to see was the bed from which the governor “crawled.”

Mr. Mandel took up residence at an Annapolis hotel and later lived for a time on the Maryland state yacht. After about six months, he got his divorce and married Dorsey, a Southern Maryland divorcee who had held local offices in St. Mary’s County. She died in 2001.

The governor’s divorce settlement was reported at the time to have cost $400,000. His salary as the state’s chief executive was $25,000. Helping to make up the difference was Irvin Kovens, a wealthy Baltimore furniture store owner, political kingmaker, and longtime friend and political supporter of Mr. Mandel’s.

In 1975, Kovens and four others would figure in a federal mail-fraud and racketeering indictment that would bring the governor down.

Central to the indictment was the Marlboro Race Track, a run-down facility in Prince George’s County with few amenities, a shoddy ambiance and a low allotment of racing days.

In 1971, Mr. Mandel vetoed legislation that would have increased the track’s racing-day allotment, and the owners wanted to sell it. They did so, at a low price, to Kovens; W. Dale Hess, a former Democratic leader of the Maryland House; and brothers William A. Rodgers and Harry W. Rodgers III. The identities of the new owners were kept secret behind false names in documents drawn up by Ernest N. Cory, a Prince George’s lawyer.

At a subsequent legislative session, the governor’s friends lobbied behind the scenes for an override of the veto, increasing the track’s racing-day allotment. When the override went through, the value of the track increased substantially, and the owners sold it at a handsome profit.

According to prosecutors, Kovens and the others paid travel expenses for the governor, bought him clothes and a diamond bracelet for his wife, and cut him in on two lucrative real estate deals.

After one mistrial, a federal jury in 1977 found Mr. Mandel and the five others guilty of defrauding the people of Maryland of their right to the “conscientious, loyal [and] faithful . . . services” of the governor.

After his sentencing in October, Mr. Mandel was stripped of his power as governor, but he returned to the State House to complete the final 451 / 2 hours of his term in January 1979 after an appeals court overturned the conviction.

In July 1979, the full Court of Appeals for the Fourth Circuit reinstated the conviction, and Mr. Mandel served 19 months in a federal prison. In 1981, President Ronald Reagan commuted his sentence to time served, and the former governor was released.

As a convicted felon, Mr. Mandel was disbarred and could no longer practice law. He found work as a consultant to a builder and as host and interviewer on a radio talk show.

But in July 1987, the U.S. Supreme Court reviewed the convictions of public officials from Kentucky who had been convicted under the same statute as Mr. Mandel.

That statute, the high court held, was intended as a protection against being defrauded out of money or property but not the loss of such “intangible rights” as honest government.

In light of the ruling, a federal judge overturned Mr. Mandel’s conviction in November 1987, and that ruling was upheld by the Court of Appeals for the Fourth Circuit a year later. Mr. Mandel was reinstated to the Maryland bar and resumed his practice of law.

Callcott said Mr. Mandel would probably be remembered more as a governor who was indicted and did jail time than as a governor who made Maryland more efficient.

“His legacy was not as large as his contributions,” Callcott said.

Climbing the ladder

Marvin Mandel was born April 19, 1920, and grew up in the Pimlico area of Baltimore in what then was a lower-middle-class, mostly Jewish neighborhood near the famed racetrack.

His father was a garment cutter, his mother a homemaker. He attended public schools and graduated from the University of Maryland and its law school. During World War II, he served in the Army in Maryland and in Texas. He became a lawyer in private practice after the war.

As a politician, Mr. Mandel never emphasized his Jewish identity, but he attended High Holy Day services and once in the Maryland State House volunteered to be the necessary 10th man for a basement memorial service for a state delegate’s father who had just died.

In the early years of his career, he had the advantage of being a Democrat in a mostly Democratic district and a Jew in a mostly Jewish district.

He married a neighborhood girl, Barbara Oberfeld, in 1941. They had two children, Gary and Ellen. While the future governor was in law school, Bootsie Mandel worked to help support them, as she would remind the media decades later when the governor sought a divorce. “We climbed the ladder together,” she would say.

There were four stepchildren from Mr. Mandel’s second marriage. A complete list of survivors could not immediately be confirmed.

When he was a young lawyer, Mr. Mandel’s clients included the owners of the striptease bars along “the Block,” near Baltimore’s harbor.

As a private citizen, after his political career had ended, after he had served his prison time and after his conviction had been voided, he practiced law again, handling a broad range of cases. He also did some lobbying before the Maryland legislature, for clients including computer systems firms and the Maryland Medical Association.

In 2003, Gov. Robert L. Ehrlich Jr. (R) named Mr. Mandel to the board of regents of the University of Maryland. He stepped down in 2009.