Specifically about your comment, impeachment is a political process and there is literally no definition of "high crimes and misdemeanors" in our constitution. If congress were to grow a pair then impeach and convict, let's say an obviously corrupt SCOTUS justice, for any reason, that person is out and there is literally no appeal. No court, not even SCOTUS could overturn such an impeachment. I just don't know what would unify the members of the two parties to do this.
Post 25, above, provides a link to all of the federal judges impeached and either acquitted or removed for their specific acts. That should give one a sense of what has risen to "high crimes and misdemeanors" under this rubric.
A Recap:
Acquittals:
-on charges of arbitrary and oppressive conduct of trials; Acquitted
-on charges of abuse of the contempt power; Acquitted
-on charges of abuse of contempt power and other misuses of office; Acquitted
-on charges of favoritism in the appointment of bankruptcy receivers; Acquitted
Removals
-on charges of mental instability and intoxication on the bench; Convicted
-on charges of refusing to hold court and waging war against the U.S. government; Convicted
-on charges of intoxication on the bench; Resigned from office, December 12, 1873, before opening of trial in the U.S. Senate.
-on charges of improper business relationship with litigants; Convicted
-on charges of abuse of power; Resigned
-on charges of favoritism in the appointment of bankruptcy receivers and practicing law while sitting as a judge; Convicted
-on charges of income tax evasion and of remaining on the bench following criminal conviction; Convicted
-on charges of perjury and conspiring to solicit a bribe; Convicted
-on charges of perjury before a federal grand jury; Convicted
-on charges of sexual assault, obstructing and impeding an official proceeding, and making false and misleading statements; Resigned
-on charges of accepting bribes and making false statements under penalty of perjury; Convicted
None was impeached for their legal theories or decisions or politics.