Gingrich arriving at the Republican Jewish Coalition event in Beverly Hills Sunday. (David McNew/Getty Images)

If Newt Gingrich is serious about becoming president of the United States, this weekend was surely the time for him to give the speech of his life. A fluke of timing put the former speaker of the House onstage Sunday for a planned foreign-policy address in front of a roomful of Republican Jewish donors in Beverly Hills, at the Republican Jewish Coalition’s $250-a-plate “Summer Bash” fundraiser. A few days earlier, his top campaign aides had quit, and the next day would be a make-or-break appearance at last night’s first major public debate among Republican contenders. The event, in the ballroom of the Beverly Hilton, honored the billionaire casino magnate and pro-Israel activist Sheldon Adelson and his wife, Miriam—who not incidentally have been Gingrich’s chief patrons. But the bond the former speaker forged with Adelson—which was supposed to bring one money and the other influence—may end up delivering neither.

Gingrich gamely tried to project optimism. “I am running for president to lead a movement of Americans who will insist on changing Washington so we can renew America,” he announced from the podium. But he made no bones about the straits he is in, and he borrowed from William Faulkner’s Nobel speech to cast himself as a martyr.  “I will endure the challenges,” Gingrich said. “And with the help of every American who wants to change Washington, we will prevail.”

The dominant story line about Gingrich’s campaign implosion last week is that his aides had despaired of weaning him from the influence of his third wife, Callista, whom he chose to squire on a Greek cruise rather than going on hayrides through the cornfields of Iowa. But it is also clear that the mass defections were, as Politico put it, “all about the Benjamins”—or, more specifically, the lack thereof. Campaign finance records aren’t due to be released before July, but according to the Washington Post, the Gingrich campaign didn’t have the $25,000 it needed to enter the crucial Iowa straw poll in August, let alone another $30,000 to buy voter lists, while Gingrich was insistent on flying chartered planes for as much as $500,000 a pop. Gingrich had declined to set up a dedicated finance committee, the paper added, and he wasn’t used to fundraising under the rules passed since he left Congress more than a decade ago—and, in the meantime, he has grown accustomed to enjoying Adelson’s largesse.

In the absence of federal filings, it isn’t clear how much Adelson, who Forbes ranked in March as the fifth-richest man in America, has contributed to Gingrich’s campaign so far. But he has been the top donor to Gingrich’s political advocacy group, American Solutions Winning for the Future, giving more than $7 million, or about 13 percent of the $52 million the group has raised since its inception in 2007. Adelson has been sufficiently invested in promoting Gingrich, especially within the American Jewish community, that he took the time last month to call the editor of New York’s Jewish Week to complain about an article he found unfair.

Yet editorial decisions at local Jewish newspapers have far less chance of influencing the Gingrich candidacy than Adelson’s own fortunes—and, as it happens, Las Vegas Sands, the source of the casino mogul’s immense wealth, is currently under investigation by the Justice Department and the Securities and Exchange Commission under the Foreign Corrupt Practices Act. The probe stems from bribery allegations lodged in a wrongful-termination lawsuit filed by the company’s former operations head in the Chinese enclave of Macau. Las Vegas Sands says it is cooperating, but since the disclosure, the company has lost more than $3.5 billion in value, or more than 11 percent, and last week Deutsche Bank booted the company off its list of short-term buy recommendations.

In other words, the largest single source of Gingrich’s backing is now, at least to some degree, both less flush than he used to be and newly at the mercy of the Obama Administration—a situation that can’t have improved the mood of Gingrich’s cash-strapped strategists as they wondered about where their next paychecks might be coming from. Last year, a person familiar with Adelson’s thinking told me that he wasn’t going to commit to new philanthropic expenditures until Sands stock hit a certain price, though it wasn’t clear just what that price was. At the time, Sands shares were hovering just below $30—a far cry from their 2007 highs of $140 but a vast improvement over their 2008 lows of less than $2—but it isn’t beyond the realm of possibility that, if the market really starts to tank, Adelson might wind up sidelining himself politically, too.

As it turned out, Adelson was a no-show at the Beverly Hilton Sunday night. His wife, Miriam, told the audience that he was fighting a bad flu—“He is really suffering, leaking from every corner of the eyes, his nose. Not his ears!” But she conspicuously failed to give Gingrich a shout-out during her turn at the dais, where she accepted the evening’s Ronald Reagan Award for her husband. Earlier in the evening, when Gingrich emerged from a VIP reception to face a horde of television cameras swarming the pre-dinner cocktail bar, she went the other way, a blur of ice-blond hair and brilliant white pantsuit click-clicking through the hotel lobby. “Pay attention to the speech. It is so good. He is such a lover of Israel,” Miriam Adelson told me, in a brief interview near the front entrance. But what about his presidential ambitions? “Let’s not talk about politics,” she said, giving a Mona Lisa smile and shaking her head as she walked away.

It was a response far short of the full-throated, fighting endorsement Gingrich might reasonably have expected from the wife and proxy of his biggest fan—at an event almost expressly designed to facilitate matchmaking between the candidate and Adelson’s fellow Republican Jewish Coalition board members and activists. Gingrich, who characteristically chose to give a 40-minute-long lecture about the history of the Middle East conflict rather than a barnstorming campaign speech, was warmly received by the audience, which obligingly booed mentions of Obama’s name and cheered Gingrich’s repeated statements about not brooking any accommodation with Hamas. But that doesn’t do much to answer the question of who, especially among fiscally conscious Republican donors, would start giving money to Gingrich’s campaign now, in the absence of a credible campaign team. (The pollster Frank Luntz managed to punk Republican Jewish Coalition head Matt Brooks into tweeting, just before Gingrich took the stage Sunday, that he would be taking over the Gingrich command.)

Which raises, for the Republican Jewish Coalition, the uncomfortable possibility that, just as Gingrich’s dependence on Adelson may turn out to be his Achilles’ heel, the group’s willingness to follow Adelson’s lead in favoring Gingrich so early on may ultimately leave it without the influence it craves over a GOP presidential field that remains highly fluid—and whose leading members like Mitt Romney and even the famously pro-Israel maybe-candidate Sarah Palin were elsewhere, enjoying other audiences.