Thomas arrived at the court with more fanfare but not much more of a paper trail than Souter. Bush plucked Thomas from the D.C. Circuit Court of Appeals, where he had appointed him less than two years earlier.
The former Reagan administration official's confirmation process was dogged by controversy after one of his former staffers, Anita Hill, accused him of sexual harassment. Thomas denied the allegations and slammed the confirmation process.
"As a black American, as far as I'm concerned it is a high-tech lynching for uppity blacks who in any way deign to think for themselves, to do for themselves, to have different ideas," Thomas said. The process echoed in the contentious confirmation of Justice Brett Kavanaugh earlier this year.
While on the court, Thomas has served as a prolific dissenter, expressing his originalist views of the law in opinions often joined by none of his fellow justices. Those opinions haven't always created Supreme Court precedent, but they have been influential in lower courts and in shaping conservative legal thought.
On the court, his greatest impact has been his willingness to do away with precedent, said Marisa Maleck, who clerked for Thomas in the 2015 term and is now a senior associate at the law firm King & Spalding.
"He says, if we got it wrong, I don't really care, we shouldn't keep getting it wrong and compounding the error," Maleck said.
Thomas' influence also extends to the executive branch. An unusually large number of his former clerks serve in the Trump administration, according to an analysis by The Associated Press. Maleck suggested that could be because of the prominent role members of the Federalist Society have played in assisting the president in staffing.
"There is a natural overlap, the small inner circle," Maleck said.
The list of former Thomas clerks in the Trump administration includes officials in influential posts such as Neomi Rao, who oversees the administration's efforts to pare back regulation. Trump recently nominated Rao to replace Kavanaugh on the D.C. Circuit Court.
The full measure of Thomas's legacy on the court is hard to judge while he remains on the bench. But Thomas is "closer to galvanizing majorities and being in majorities than he ever has been, and so maybe that gives us a sense," according to Richmond University's Tobias.
The legacy could instantly grow should the 70-year-old Thomas retire before 2020. There is some speculation that he could do so in order to assure Trump gets to select his replacement.
"I don't know if he wants to serve another eight years, but he might," Tobias said. "It's hard to imagine him sitting at home and playing pingpong."