Heads spun Tuesday when __Donald Trump__decided that the best course for righting his campaign’s sinking ship would be to bring on alt-right newsman Stephen Bannon as chief executive. It was a decision that appeared to double down on some of the Trump’s campaigns most fringe elements and self-destructive impulses—which seem to be the reason the ship has been sinking in the first place—leaving many wondering: Who thought this was a good idea?

The answer, according to several reports, is the conservative, anti-establishment, aggressively anti-Clinton hedge-fund billionaire Robert Mercer, and his daughter Rebekah. The Mercers, who initially put $13.5 million into a PAC that supported Ted Cruz’s presidential bid, reportedly surprised their friends when they swung their support behind Trump after the Texas senator dropped out. According to Bloomberg, Rebekah met with Ivanka Trump (the campaign’s de facto First Lady ) and her husband, Jared Kusher (until yesterday, the campaign’s de facto manager) earlier this year to win over her family’s support.

By the time Cruz refused to endorse Trump onstage at the Republican National Convention, the notoriously private family released a statement in support of the billionaire developer that concluded, “We need all hands on deck to ensure that Mr. Trump prevails.” For the Mercers, that apparently included bringing Bannon on board. Rebekah reportedly broached the topic with a downtrodden Trump at a Hamptons fund-raiser hosted by Jets owner Woody Johnson over the weekend, according to The Washington Post. The Post cites three sources who say that she confronted him about reports that his staffers were urging him to tone down his rhetoric and professionalize his campaign; he reportedly asked her how he could fill his inner circle with voices that more closely mirrored his own. That’s when she brought up Bannon’s name. By Sunday, the two were golfing together at the Trump National Golf Club in New Jersey. By Tuesday, it was announced that the Breitbart exec had the job.

The Mercers’ ties to Bannon run deep. According to Bloomberg, the family first invested $10 million in Breitbart News in 2011, and later worked together to turn the book Clinton Cash—a damning look at the Clinton's foundation—into a Mercer-financed documentary. (Bloomberg noted that Mercer sent his 203-foot yacht to its premier at Cannes). Bannon also reportedly serves as an adviser to one of the family’s advocacy groups in New York, which shares an address with Cambridge Analytica, a data firm in which the Mercers are investors. It just so happens that the Trump campaign recently decided to use the firm’s services, according to The Hill, which cited the decision as another example of the Mercers’ influence within the Trump campaign.

This kind of influence between wealthy donor and candidate is the exact sort of relationship for which Trump has slammed Hillary Clinton in the past. But it makes sense that a New York billionaire so swayed by his own daughter would take a cue from another New York billionaire father-daughter political partnership. (Rebekah, according to The Hill, also happens to live in one of Trump’s buildings, as Ivanka also does.) While Trump's daughter is off yachting with interesting company in Croatia, it seems another billionaire heiress has caught his ear.