The price of consensus for Mercer's "help" in retrospect was obviously that Trump soften his deportation stance. Bloomberg's story here in June completely misses the signficance of the Mercers' libertarianism.
The Hill had the story already on August 17, here, the day Trump shook up his campaign by hiring Stephen Bannon as CEO and Kellyanne Conway as campaign manager, detailing Mercer's links to Stanford, the Heritage Foundation, BREITBART, the Ted Cruz campaign and libertarian think tank CATO:
“The Mercers basically own this campaign,” said a source who has worked with Rebekah Mercer in her political activities. “They have installed their people. ... And now they’ve got their data firm in there.” ... Little has been written about the Mercers because they avoid the public spotlight, but conservative sources who know the family, who spoke on condition of anonymity, described them as “kind, civic-minded people and consensus-builders.” ... But that source, who has worked with Mercer in some of her other political ventures, said it was a surprise to some people that the Mercers had swung so forcefully behind Trump, given her ideological bent. “She identifies as a libertarian. At least she always did,” the source said, adding that Mercer was a big supporter of libertarian think tanks like the Goldwater Institute and Cato. “With Bekah you always had to prove your libertarian racing stripes,” the source added. “This seems really strange.”