In 2009 the SCOTUS found that any judge who exhibits an "appearance of bias" or where an objective person would harbor a "suspicion of bias" in judge, then that judge must recuse themself.There is no mandatory recusal standard for the supreme court.
Supreme Court Justices, who are judges, are not above their own law.
At least you are no longer arguing the obvious: that Kagan and Ginsburg exhibited bias on the fed looming over states having to redact the word "marriage"..
Kagan and Ginsburge displayed bias by doing what?
Legally marrying someone- just like other justice have done?
Supreme Court justices decide for themselves whether to recuse themselves.