Oversight

I read this quote today from Henry Waxman:

Waxman explained that “you must ask the questions” and “you must do the oversight if we’re going to keep people honest, if we’re going to provide the checks and balances that our Constitution envisions.” By pressing forward with the investigation, investigators have revealed a disturbing pattern by Doan to mislead and cover-up her true intent regarding these partisan briefings.

And I agree with Waxman. But my question is this. Investigations usually result in political pressure = accountability. But what happens when political pressure doesn't do anything? In my lifetime, I only recall the occasions of Clinton and Nixon's impeachment where Congress actually implemented a consequence. I suspect there may others, but in general they are rare. Congress, in general, has historically depended on the cooperation of the Executive in bowing to "pressure".

So Waxman and Congress can investigate until the cows come home but I really don't think it's going to result in anything because Bush refuses to have any respect for Congress, voters, and the Constitution. So until Congress actually implements a consequence, i.e. contempt of Congress, impeachment, prejury charges, or the like, isn't it all becoming redundant hot air?