Lying and slander are serious aveiros, and it makes no difference that the victim is a nochri. JacKKK is a rosho merusha. Any mitzvos he may do (and I’m not convinced he does any) are worthless, because he is such a hateful liar.
Thomas has never done anything unethical in his entire career. If a friend invites him to come with him on vacation, there is no reason in the world why he should turn it down. There is no judge anywhere who would turn it down. Harlan Crow is a personal friend of his, and occasionally invites him to travel with him, or does him favors; any decent person should be happy for him.
If Crow would ever have a case come before the Supreme Court, obviously Thomas would recuse himself; but that has never happened, and there’s no prospect of it ever happening.
Likewise if a case ever came before the court to which Mrs Thomas was a party, he would obviously have to recuse himself, but that has never happened either. The fact that she is active politically is completely irrelevant, and it is NEVER the practice of judges to recuse themselves just because a family member is politically active. That would be a ridiculous and unsustainable rule.
Consider Reinhardt, who used to be chief judge of the 9th circuit, and whose wife was the head of the Southern California chapter of the ACLU. He would recuse himself only if that chapter was party to a case; but if it was any other chapter he would NOT recuse himself, because his wife was not a party. That is the standard, and Thomas has every right to stick to it. Anyone criticizing him for it is dishonest.