This passage from Jane Mayer’s article in The New Yorker about Robert Mercer is fascinating:

Cambridge Analytica is not the only data-driven political project that the Mercers have backed. In 2013, at a conservative conference in Palm Beach, an oil tycoon named William Lee Hanley, who had commissioned some polls from Patrick Caddell, asked him to show the data to Mercer and Bannon, who were at the event. The data showed mounting anger toward wealthy élites, who many Americans believed had corrupted the government so that it served only their interests. There was a hunger for a populist Presidential candidate who would run against the major political parties and the ruling class. The data “showed that someone could just walk into this election and sweep it,” Caddell told me. When Mercer saw the numbers, he asked for the polling to be repeated. Caddell got the same results. “It was stunning,” he said. “The country was on the verge of an uprising against its leaders. I just fell over!”

Until Election Day in 2016, Mercer and Hanley—two of the richest men in America—paid Caddell to keep collecting polling data that enabled them to exploit the public’s resentment of élites such as themselves. Caddell’s original goal was to persuade his sponsors to back an independent candidate, but they never did. In 2014, Caddell and two partners went public with what they called the Candidate Smith project, which promoted data suggesting that the public wanted a “Mr. Smith Goes to Washington” figure—an outsider—as President. During the next year or so, Caddell’s poll numbers tilted more and more away from the establishment. Caddell’s partner Bob Perkins, an advertising executive and a former finance director of the Republican Party, told me, “By then, it was clear there wouldn’t be a third-party candidate. But we thought that a Republican who harnessed the angst had a real chance.” At one point, Caddell tested all the declared Presidential candidates, including Trump, as a possible Mr. Smith. “People didn’t think Trump had the temperament to be President,” Caddell said. “He clearly wasn’t the best Smith, but he was the only Smith. He was the only one with the resources and the name recognition.” As Bernie Sanders’s campaign showed, the populist rebellion wasn’t partisan. Caddell worried, though, that there were dark undertones in the numbers: Americans were increasingly yearning for a “strong man” to fix the country.

Caddell circulated his research to anyone who would listen, and that included people inside the Trump campaign. “Pat Caddell is like an Old Testament prophet,” Bannon said. “He’s been talking about alienation of the voters for twenty-five years, and people didn’t pay attention—but he’s a brilliant guy, and he nailed it.” The political consultant and strategist Roger Stone, who is a longtime Trump confidant, was fascinated by the research, and he forwarded a memo about it to Trump. Caddell said that he spoke with Trump about “some of the data,” but noted, “With Trump, it’s all instinct—he is not exactly a deep-dive thinker.”

Robert Mercer, too, was kept informed. Perkins said, “He just loves the numbers. Most people say, ‘Tell me what you think—don’t show me the numbers.’ But he’s, like, ‘Give me the numbers!’ ”

Agree or not, the group’s deep understanding of public perception and belief in data (“When Mercer saw the numbers, he asked for the polling to be repeated”) is incredibly impressive.