Your point about Stevens' conviction: prosecutorial misconduct is a completely separate issue from guilt and innocence.  Ted (or any other defendant) could be guilty as Judas and the judge would still have dismissed the case once the U.S. attorneys admitted they had suppressed discoverable evidence that could have had a bearing on the verdict.

Personally, I agree with you that Ted Stevens wasn't corrupt (especially in our egregious post-Citizens United sense of the word).  But he had the same problem others do after too damn many years inside the bubble: he had forgotten how ordinary people saw things.  The privileges and emoluments of office, both monetary and emotional, had become entitlements to him.  He couldn't remember living without them.  The old, classic Ted Stevens would never have made the kind of rookie errors with Bill Allen that the decrepit, purblind Stevens made.  He would have been infinitely better off to  retire gracefully in 2008.