Rebekah Mercer, left, with parents Robert and Diane Mercer. Trump...

Rebekah Mercer, left, with parents Robert and Diane Mercer. Trump "got his footing" when he started talking to the Mercers, according to a Republican source. Credit: PatrickMcMullan. / Sylvain Gaboury

A mosaic of factors, large and small, propelled Donald Trump’s defeat of Hillary Clinton on Election Day. One had its roots at a small fundraiser on Long Island.

Trump, on an August night after he became the GOP presidential nominee, was raising money with deep-pocketed donors at the East Hampton home of New York Jets owner Woody Johnson. Trump huddled with Rebekah Mercer — daughter of Long Island GOP megadonor Robert Mercer, a hedge-fund billionaire — about reshaping the helm of his flailing campaign with voices more like his own, according to published reports.

A fast-moving series of calls and meetings that followed led to the recruitment of Stephen Bannon, head of the conservative website Breitbart News, as campaign CEO, and the promotion of veteran GOP pollster Kellyanne Conway to campaign manager. The shake-up ended the two-month reign of campaign chairman Paul Manafort, who had tried to soften Trump’s style to appeal to a broader range of voters.

The Mercers, who had spent millions of dollars backing Trump rival Sen. Ted Cruz (R-Texas) earlier in the race, now were on board. Conway also came from the Cruz camp. Though it wasn’t the crucial piece in Trump’s path to victory, it was an important one, allies said.

“From my view, Trump was adrift before he brought them in,” said a New York Republican, who, like others, spoke on condition of anonymity out of concern about offending the Mercers. “I think, in a lot of ways, when Donald Trump started talking to the Mercers, he got his footing. The Mercers steered Steve Bannon and Kellyanne Conway to him. There was a lot of criticism when they took over — but look at the result.”

War of words

The conventions had just concluded and Clinton had widened her lead in the polls. Trump embroiled himself in a war of words with Khizr Khan, father of a slain Muslim U.S. Army captain, and later with Alicia Machado, a former Miss Universe he had demeaned as “Miss Piggy” because of weight gain. The new team got Trump back to talking jobs, immigration and Clinton.

“When Robert and Rebekah got involved and decided to make a commitment to Donald Trump, it was a great boost,” said Suffolk County Republican chairman John Jay LaValle. “They got together and the wheels were in motion.”

LaValle said the Mercers’ involvement “allayed a lot of fears among conservatives” about Trump at a time some Republicans were abandoning their candidate. On Tuesday, Robert Mercer was among those on hand at Trump’s victory party at the Hilton in midtown Manhattan, sources said. Unrest about jobs and immigration, Clinton’s low favorability ratings and email scandals, and low turnout by key Democratic supporters likely all played bigger roles in the outcome, observers said, but Trump’s campaign shake-up made a difference, too.

“I saw immediately a more disciplined, organized, substantive campaign the moment Kellyanne came on board,” said Rep. Lee Zeldin (R-Shirley), who had worked with Conway on his successful 2014 congressional bid. “It made an immediate impact in every aspect of the campaign.”

Zeldin praised Conway as having “amazing instincts” about politics and ability to hone down six paragraphs of material “into six words” that voters can grasp.

Robert Mercer, 70, is co-CEO of Renaissance Technologies, a hedge fund headquartered in East Setauket and founded by James Simons, a megadonor to Democrats. According to several profiles, Mercer plays in $100,000 poker games, backs a return to the gold standard, owns a number of yachts, maintains a machine-gun collection and lives in an elaborate mansion in Head of the Harbor that includes a $2.7 million model-train set.

Rebekah Mercer, 42, lives in an apartment at Trump Place along Manhattan’s Upper West Side, records show. She reportedly has been the driving force in the family’s political involvement. She was named Friday to Trump’s transition committee.

Spent $32M on campaigns

Robert Mercer became a major donor to conservative causes and candidates after the U.S. Supreme Court’s “Citizens United” decision, which removed the limits on political spending by so-called Super PACs, or political action committees. From 2010 through last summer, Mercer spent a reported $32 million on political races. He’s also given to anti-abortion groups and an Oregon institute that questions global warming.

He invested $10 million in Breitbart News in 2011, sources told Politico and Bloomberg News. Mercer also was a major funder of the Government Accountability Institute, which helped bankroll an anti-Hillary book called “Clinton Cash,” according to published reports. They also own a stake in Cambridge Analytica, a voter-data firm that backs conservative candidates.

“They see the establishment as a very real threat to freedom in America, and they see the need to defeat it,” Brent Bozell, president of the Media Research Center, told Politico in September.

A request for comment, placed with the Mercer Family Foundation, wasn’t immediately returned.

Even at political events, he doesn’t talk politics much, a source said.

“He’s an extremely bright individual,” LaValle said. “He doesn’t want to seem to be in the limelight of politics but he wants to have a positive effect.”

Zeldin called Mercer a “very proud, patriotic American who has a passionate love of his country.”

A computer programmer by trade, Mercer is said to be reclusive, “extremely private” and a man of few words. In a 2014 profile, Bloomberg Politics noted that, at an awards ceremony, Mercer told the crowd he realized he was supposed to speak for an hour, adding, “which, by the way, is more than I typically talk in a month.”

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