Questioning the Supreme Court and other government branches needs to stay within the range of fair criticism or "run the risk in our society of undermining institutions that we need to preserve our liberties," Justice Clarence Thomas said Thursday.

Thomas also told an audience at the University of Florida law school that some comments he hears about the court "border on being irresponsible."

He didn't speak specifically about the court's recent decision on campaign financing or mention President Barack Obama. But Thomas' comments come a week after Obama took the rare step of openly criticizing the decision during his State of the Union speech.

Thomas supported the 5-4 ruling that allows companies and unions to spend freely on ads that promote or target candidates by name.

Thomas said the court should be questioned but is bothered by some rhetoric with "the idea of assigning ulterior motives to opinions that people don't agree with, rather than saying simply that the court doesn't agree with my argument."

When Tom Delay, John Cornyn, James Dobson, Jerry Falwell and Pat Robertson declare open warfare against the activist Supreme Court, Thomas stays mute. Kinda like his behavior on the court except when he acts like an activist.