I wrote earlier that Justice Thomas has no plans to step down. At HotAir, Allahpundit suggests that he should step down while a Republican president and Republican senate are available to replace him. In the Obama years, liberals sometimes urged Justice Ginsburg to step down for similar reasons.
Supreme Court justices generally seem to be careful to time their retirements to allow ideologically compatible presidents to nominate their replacements. Justice White may have been more conservative than most Democratic appointees, certainly by the end of his time on the Court, but he seemed to prefer having a Democratic president (and Senate) replace him. Make the requisite reversals and you can say the same thing about Justice O’Connor’s departure in 2006. (White was replaced by Justice Ginsburg, O’Connor by Justice Alito.)
The last time a justice was replaced by a president on the other side of the ideological divide was 28 years ago, when Justice Thomas himself replaced Justice Marshall. Justice Scalia, of course, died in office during a Democratic presidency, but a Republican appointee ultimately filled his seat. The scenario that activists on each side worry most about hasn’t happened yet in our polarized era.