Breyer — professorial, practical and moderately liberal — wrote many of the court's legally important but less glamorous decisions and sought, behind the scenes, to build consensus for centrist decisions on a conservative court.

Breyer's retirement gives President Biden his first opportunity to name a new justice to the court. During the 2020 campaign, he pledged to name a Black woman if he got the chance. The two leading contenders are said to be federal Judge Ketanji Brown Jackson, who was on President Barack Obama's shortlist for the court in 2016, and California Supreme Court Justice Leondra Kruger, who served as assistant and then deputy solicitor general in both Democratic and Republican administrations prior to her nomination to California's highest court.