All federal judges (not magistrate judges) get lifetime appointments. It's a great job if you can get it, but if you think absolute power would breed corruption, you'd be surprised. In practice, federal judges and their clerks (at least in northern California) seem more detailed with their decisions, not because of any inherent superiority in intelligence, but because it is harder for litigants to get to federal court. The federal courts' more restrictive barrier to entry (federal courts are courts of "limited jurisdiction") leaves them with fewer cases and more time to analyze them. More time to do something usually leads to an increase in quality.
In contrast, state courts get flooded with lots of weak cases and after a while, most judges, unless they have exceptional work ethic, tend to become jaded and/or extensively delegate to their smart, hard-working clerks. (By the way, the Hon. Judge Kevin McKenney of Santa Clara Superior Court comes to mind as one of the hardest-working judges in California.)
The WSJ recently wrote an article about a Los Angeles federal judge who is said to be out of control. It's a major embarrassment to the system, but kudos to the WSJ for calling out government corruption when it sees it. Here's an interesting line from the WSJ's article today, 8/8/08 (A9):
"Is the federal system well equipped to deal with incorrigible behavior by judges?"..."No, not where the behavior doesn't rise to the level of impeachment."
That's not a good sign. Would America's founders tolerate a government that included virtually unaccountable judges? I don't think so--they would have wanted some substantive difference between a British king and a federal judge. What makes the issue complex is that America's founders also promoted the "separation of powers" doctrine--the Constitutional principle that gives judges their independence--precisely so that federal judges would feel insulated from public opinion and the executive and legislative branches.
I'm not sure how to balance the tension between judicial independence and government accountability. Judicial independence sounds good in theory, but the federal courts' interpretation of the Patriot Act seems to indicate that judges, despite lifetime appointments, tend to move in lockstep with the herd, waiting until abuses are rampant before stopping them. At the end of the day, the newspapers and the media may be the only entities that can keep judges from running amok.
Update on November 10, 2008: from the SJ Mercury News, 10/10/08, John Corvino:
It's worth remembering, however, that the courts follow social trends more often than they set them. When the U.S. Supreme Court struck down laws against interracial marriage in Loving v. Virginia, the majority of states already had repealed such laws.
More on judges and judicial power HERE.