It's been done so seldom most people don't even know it can be done. What? Debenching (impeaching) a Supreme Court Justice. Yes, just as with impeaching a President, the Legislature has the power to debench an unsatisfactory Justice, and it's been done.
It seems that the Court usurping the duties sovereign to the Legislature should be good and sufficient grounds for debenching the entire lot of Justices who continue to vote their personal ideologies rather than stick to the strict letter of Constitutional law.