Sheldon G. Adelson, a billionaire casino tycoon and free-spending political donor who helped bankroll conservative candidates in the United States and Israel, and who pushed the governments of both countries to reject the establishment of a Palestinian state alongside Israel, died Jan. 11 in Malibu, Calif. He was 87.

The cause was complications related to treatment for non-Hodgkin’s lymphoma, according to a company statement.

Mr. Adelson (pronounced ADD-ul-son), who fought his way up from an arduous childhood in Boston, was a vivid and polarizing character, a serial entrepreneur who transformed gambling in Las Vegas and Macao and brought the same bare-knuckled approach to the exercise of political influence.

One of the world’s richest self-made men, he amassed an estimated fortune at one point this decade valued at $40 billion — Forbes now lists it at $35 billion — and used much of it to advance conservative causes and leaders, including a $25 million donation to help elect Donald Trump as president in 2016. He also played a sizable role in underwriting Israeli Prime Minister Benjamin Netanyahu’s return to power in 2009.

In Jerusalem and Washington, Mr. Adelson brandished his money and influence to advance his favorite cause: a strong Israel that precludes a Palestinian state. He also started and bought newspapers in Nevada and Israel that promoted his views.

Little known outside the business world for much of his life, Mr. Adelson vaulted to the forefront of national politics in 2012, when he and his wife buoyed the faltering presidential campaign of former House speaker Newt Gingrich (R-Ga.) with tens of millions of dollars in donations to a political action committee.

Gingrich began calling Palestinians an “invented” people and playing up support for Israel’s West Bank settlements as a cornerstone of U.S. foreign policy. Gingrich’s bid collapsed, but Mr. Adelson’s jaw-dropping financial support showed that he was willing to invest heavily in politicians who shared his beliefs. He and his wife, Miriam, ended up giving an estimated $93 million in the 2012 election cycle to an alphabet soup of conservative PACs backing Republican office-seekers — not including contributions to groups that were not required to disclose their donors.

The Adelson primary

As Barack Obama’s two-term presidency was ending, Mr. Adelson doubled down on the GOP’s struggles to nominate a winning candidate in 2016. Dangling up to $30 million as bait, he conducted what journalists called “the Adelson primary,” in which aspiring presidential nominees traveled to his Venetian hotel and casino in Las Vegas to solicit his money and his blessing.

He interrogated many of the 17 GOP aspirants in 2016 on their support for Israel. The process helped end the candidacy of early front-runner Jeb Bush, the former Florida governor, and elevated Sen. Marco Rubio (Fla.) to national prominence. Ultimately, Mr. Adelson endorsed New York businessman Trump before the GOP convention. According to Open Secrets, a nonprofit website that tracks campaign contributions, he and Miriam, his second wife, gave $83 million to Republicans in the 2016 election cycle.

Early in the campaign, Trump had called himself “sort of a neutral guy” on the Israeli-Palestinian conflict, but Mr. Adelson’s views were soon reflected in the candidate’s platform. As the year wore on, Mr. Adelson earmarked $25 million for a Trump PAC and, after the election, he made a record-breaking $5 million donation to Trump’s inaugural committee.

In office, Trump renounced more than five decades of U.S. foreign policy that called for a two-state solution to the Israeli-Palestinian conflict. He formally recognized Jerusalem — a city that Palestinians, as well as Israelis, claim as their own — as the capital of Israel. He also moved the U.S. Embassy there from Tel Aviv, undermining the American role as an ostensibly neutral arbiter in a region brimming with religious tension and violence.

Mr. Adelson, a driving force in the effort to relocate the embassy, pledged millions of dollars to the State Department to help pay for a new building. Although the legality of fulfilling that offer was dubious, it brought into sharper focus his role as a key player in the Trump administration’s relationship with Israel.

In May 2018, Mr. Adelson and his wife had prime seats at the formal dedication of the new embassy in Jerusalem. Less than 50 miles away, conflict was erupting on the Gaza border, where dozens of Palestinian protesters were killed by Israeli soldiers. His Las Vegas newspaper, the Review-Journal, ran a front-page editorial, written by Miriam Adelson, with a headline proclaiming, “A great day for Israel — and for America.”

Mr. Adelson was also outspoken about his objections to Obama’s diplomatic outreach to Iran — a potent regional adversary of Israel — and the multinational nuclear deal that resulted from that effort in 2015. In a 2013 speech at Yeshiva University in New York, Mr. Adelson suggested that U.S. negotiators should use the threat of a nuclear attack on Iran to bring Tehran to the table.

“If you really want peace,” he said, “it’s very simple to send a message to your opposition.”

In May 2018, Trump withdrew from the nuclear deal, which the president called a “giant fiction.”

Mr. Adelson also gave generously to political causes unrelated to Israel — to campaigns against marijuana legalization, for instance, and to the fight against Internet wagering and online poker, which many in his industry viewed as an effort to safeguard his bricks-and-mortar casino empire in the guise of moral indignation. The gambling industry’s main lobbying group also expressed surprise and dismay at his position.

“This is not a money issue with me,” Mr. Adelson told Politico in 2014. “This is a moral issue. . . . When I started to imagine what would happen with legalized Internet gaming, it scared the heck out of me . . . because of what it’s going to do to our society. Can you know your customer? No! Can you prevent money laundering? No! Can you prevent underage children?”

The boy entrepreneur

Sheldon Gary Adelson was born in Boston’s Dorchester neighborhood on Aug. 4, 1933. His father was a Jewish Lithuanian immigrant who worked as a cabdriver. His British-born mother ran a knitting business from the tenement where he grew up with three siblings.

At 12, Mr. Adelson often recalled, he began selling newspapers, but he disliked sharing profits. So instead, he went into the business of leasing “newspaper corners” with the help of an uncle who lent him the money to get started. “My uncle said, ‘If I give you the $200, you have to show up every Tuesday with a $15 payment plus interest,’ ” Mr. Adelson told the Los Angeles Times. “I said, ‘Wait, I gotta pay this back?’ He taught me about loans and about interest.”

After four years in the newspaper business, he said, he borrowed thousands of dollars from his uncle to buy a company that operated Boston-area candy-vending machines, some of which he placed in all-night gas stations catering to cabdrivers like his father.

He attended City College of New York but dropped out to train as a court reporter. After Army service, he entered into a variety of short-lived endeavors. He sold toiletry travel kits to hotels. He marketed a compound to de-ice car windows. He worked as a court reporter, a mortgage banker and a tour operator. He invested in real estate. He faced dozens of lawsuits from debt collectors. He made and lost a fortune twice.

In 1979, Mr. Adelson and partners, taking note of the burgeoning personal-computer business, launched the Computer Dealers Exposition, or Comdex, in Las Vegas. The trade conference grew quickly and, after it was opened to the general public, drew hundreds of thousands of visitors to see the latest innovations in personal computers. Travel, hotel rooms, catalogues, display space on the show floor — all of it profited Mr. Adelson.

The Interface Group, the company set up to manage Comdex, was soon running a full calendar of such events, many of them at the Sands Expo and Convention Center, which Mr. Adelson opened in 1990.

Changes in the computer business diminished the role of Comdex, which Mr. Adelson sold for $800 million in 1995 to Japanese mogul Masayoshi Son. A few years after the sale, Mr. Adelson’s two sons from his first marriage sued him, alleging that he had understated the value of Comdex to cheat them. Mr. Adelson prevailed in 2001, but the lawsuit exposed the drug addiction that in 2005 claimed the life of his eldest son, Mitchell.

His first marriage, to the former Sandra Shapiro, ended in divorce. In 1991, he married Miriam Ochshorn, an Israeli-born internist and medical researcher who specialized in drug addiction treatment. In addition to his wife, survivors include two children from his first marriage, Gary Adelson and Shelley Adelson; and two sons from his second marriage, Adam Adelson and Matan Adelson; two stepchildren, Yasmin Lukatz and Sivan Dumont; and 11 grandchildren.

Into the casino business

In 1988, Mr. Adelson and his partners bought the aging Sands Hotel and Casino, which had attained a louche appeal in the 1960s as the Las Vegas hangout of Frank Sinatra’s Rat Pack. In November 1996, the Sands was demolished to make room for a Venice-themed hotel and casino to compete with Steve Wynn’s Mirage, Treasure Island and (then under construction) Bellagio.

When it opened in 1999, the Venetian featured high-end restaurants and shops, an indoor piazza bathed with faux Adriatic light, a reproduction of the bell tower in St. Mark’s Square and an indoor waterway with singing gondoliers.

“No, it’s not like Venice,” Mr. Adelson told New York magazine. “It’s better than Venice!”

Michael Green, a historian at the University of Nevada at Las Vegas, said Mr. Adelson “brought an audacious vision of everything a resort could do to make money besides gambling. Before long, they were copying it all over the world.”

As he neared 70, in the early 2000s, Mr. Adelson made the most audacious move of his career — entering the casino market of Macao. The former Portuguese colony and seaport had become a special district of China a few years earlier.

When he arrived in Macao, Mr. Adelson later said in court testimony, it was “a seedy backwater of a gambling den” that was “prostitution-infested, crime-infested . . . everything wrong that would never happen in a state like Nevada, ever.”

Mr. Adelson outmaneuvered several competitors to win one of two coveted slots for new casinos. Mr. Adelson’s first Asian casino, Sands Macao, opened in 2004. The same year, his company, Las Vegas Sands, went public, making Mr. Adelson a billionaire several times over.

By the time he opened the extravagant, $2.4 billion Venetian Macao in 2007, Macao had surpassed Las Vegas as the world’s largest gambling market. Mr. Adelson then expanded to Singapore, opening the $5.5 billion Marina Bay Sands in 2010.

But the casino business suffered during the global financial crisis, and Mr. Adelson became embroiled in legal difficulties, including allegations that underworld figures were welcome and frequent guests at his Asian properties.

According to reports in the Wall Street Journal, Mr. Adelson’s company was involved in questionable financial arrangements in Asia. Those arrangements were said to have included $50 million in payments to a Chinese businessman who helped ease the way for the Macao casinos.

The U.S. government charged Las Vegas Sands with violating the Foreign Corrupt Practices Act, and in 2016 and 2017, the company paid more than $15 million in civil and criminal penalties.

Mr. Adelson and his family invested $1 billion to keep Las Vegas Sands afloat in the aftermath of the Great Recession, and the company went on to report a healthy recovery, thanks in large part to its casinos in Macao.

Managing the image

Mr. Adelson’s image has been burnished by many significant philanthropic contributions. He gave more than $65 million to Israeli universities and think tanks, $25 million to the Yad Vashem Holocaust memorial and hundreds of millions to educational and cultural exchange programs.

He also used his money to launch or buy media outlets that served as a megaphone for his political causes and a means of countering criticism of his business practices.

To combat liberal influence in Israel, especially support for a two-state solution to the Israeli-Palestinian conflict, he started a newspaper in 2007 that blankets the nation with free copies. The Israel Hayom, which is owned through an Adelson relative, has been a consistent backer of Netanyahu’s Likud coalition, an advocate of active Israeli settlement of the West Bank, and a foe of any Palestinian state.

Reporters and editors for the Las Vegas Review-Journal learned after the fact that Mr. Adelson had purchased their newspaper in late 2015 for $140 million, a price publishing consultants said was significantly higher than market value. The deal was arranged by Mr. Adelson’s son-in-law through a holding company. Dissenting editors were soon gone, and the new team began to vet all stories alluding to Mr. Adelson and his many legal disputes.

Over the years, Mr. Adelson had brought defamation suits against reporters. He drove at least one — John L. Smith, a prominent Review-Journal columnistinto bankruptcy, although the lawsuit, over errors in a book by Smith, was eventually dropped.

Despite his financial and political muscle, Mr. Adelson never abandoned the persona of the scrappy underdog. He was also an aggressive micromanager, according to a New Yorker article that recounted how he once became impatient with a typist who had made a couple of errors in a letter. “Adelson sat down and showed her how it was done — at ninety words a minute.”

He took unabashed pride in his success, introducing himself as “the richest Jew in the world,” and he cultivated the image of a mercurial patron of people and causes.

An incident in 2007 exemplified Mr. Adelson’s style as a power broker. For years a generous donor to the American Israel Public Affairs Committee, he kicked in $10 million extra for AIPAC’s posh new H Street NW headquarters in Washington. But before the building opened its doors, he took umbrage at AIPAC’s support for increased financial aid to Palestinians, whose “only purpose is to destroy Israel.” He immediately pulled back his money, according to New York magazine.

He also was a generous donor and active member of the Republican Jewish Coalition, a pro-Israel group with access to leading members of the GOP.

Mr. Adelson had suffered since 2001 from a peripheral neuropathy, which made it difficult to walk, and he would appear in court riding a motorized scooter. Despite declining health, Mr. Adelson maintained active control of his business and political interests until the end. As his fortunes waxed and waned, although his preferred candidates sometimes lost elections, he seemed unruffled.

“Everything is cyclical,” he told the publication Casino Journal in 2014. “It’s like gambling. Sometimes you’re up, sometimes you’re down.”