[Thane_Banquo]

Sorry, should read, "If separation-of-powers means that Congress cannot subpoena judges, then why is Congress allowed to subpoene the executive, a practice that has been tested by those same courts and found to be Constitutional?

[Hodar]

http://en.wikipedia.org/wiki/Impeachment_in_the_United_States

Should answer your questions ... Judges have been removed before.