Why the Mercers, Trump's biggest 2016 backers, have bailed on him

The numbers tell the story. In 2016, Robert Mercer, the former co-CEO of hedge fund Renaissance Technologies, and his wife, Diana, donated $15.5 million to a variety of different organizations to help elect Trump, and they put up another $1 million for the inaugural committee. They also provided substantial support to Breitbart, which at times seemed to function as an extra arm of the Trump campaign. The Washington Post reported they spent more than $49 million on political activities in 2016 and that year’s election cycle. “The Mercers laid the groundwork for the Trump revolution,” Steve Bannon said in 2017. In addition to the millions the Mercers pumped into Trump’s election, they spent $10 million on Breitbart News and millions more on Cambridge Analytica, the data firm cofounded by Robert Mercer in 2013.

But in 2018 the Mercers donated only $400,000 to the pro-Trump Great America PAC, according to the Center for Responsive Politics. Their total political spending dropped to $2.9 million last year. Sources said the Mercers cut back their spending because they felt scarred by the press scrutiny that followed their association with Trump. Two sources said Rebekah’s divorce from her husband is also motivating her to keep a low profile. “This whole thing did not end up well for them,” former Trump adviser Sam Nunberg told me. “They’ve been destroyed,” a former West Wing official said. A former Renaissance executive said: “Bob views all his political spending as a bad investment.” (The Mercers did not respond to requests for comment.)