Monday's news that FBI special agents in New York executed search warrants on the office of President Trump's personal lawyer, Michael Cohen, is just another reason why, as an old colleague of mine said recently, "If I were the subject of a Bob Mueller-led investigation, I'd be peeing my pants." What today's action demonstrates is that the special counsel is not only conducting a serious investigation of Russia interference in our democracy, and of those U.S. persons who may have colluded or conspired or otherwise enabled it, but a thorough one.