Why Did Carter Get No SCOTUS Appointments?

[Donerail]

Because the Justices are individuals, with their own personal desires and wills, and partisan considerations can rank rather low on their list of priorities.

To your specific point, Carter tried to get Marshall to retire and Marshall told him to eat sh**t and die.

[Donerail]

Not for nothing, but Thomas has publicly said time & time again that he'll die on the bench, ideology be damned.

It's difficult to see Thomas retiring unless he could ensure he is replaced not just by a conservative justice, but by someone in his particular mold. Jim Ho on the 5th Circuit, who's a former Thomas clerk, may come close based on his tenure so far, but I don't know if anyone who exactly mirrors Thomas exists anywhere.

All that said, I think Thomas wants to hold on until he gets to overturn Bakke/Grutter/Fisher.

[Donerail]

Thomas retirement rumors from usually reliable sources have occasionally bubbled up. I doubt it'll be in the next few years (unlike Alito, I think he likes the job) but you shouldn't take him at his word here either; the justices are politicians.