Leo and the Federalist Society have been connected with Trump since his first campaign in 2016, when he promised that "We're going to have great judges, conservative, all picked by the Federalist Society."
Trump was also advised on his Supreme Court picks by Leo, who, along with other attorneys, helped him assemble lists of potential justices that were used to select his three nominees to the court.
Shortly after Justice Anthony Kennedy announced his retirement in 2018, Leo said the president had "called and asked to meet and suggested the idea of doing a list."
The seat ended up being filled by Justice Brett Kavanaugh, and Trump said during a 2019 event that Leo and others worked "very hard" on the list of justices.