Take a look at Thomas Ricks’s “Fiasco,” the best account yet of how the U.S. occupation of Iraq was mismanaged. The prime villain in that book is Donald Rumsfeld, whose delusional thinking and penchant for power games undermined whatever chances for success the United States might have had. Then read Mr. Lieberman’s May 2004 op-ed article in The Wall Street Journal, “Let Us Have Faith,” in which he urged Mr. Rumsfeld not to resign over the Abu Ghraib scandal, because his removal “would delight foreign and domestic opponents of America’s presence in Iraq.”

And that’s just one example of Mr. Lieberman’s bad judgment. He has been wrong at every step of the march into the Iraq quagmire — all the while accusing anyone who disagreed with him of endangering national security. Again, on what planet would Mr. Lieberman be considered “sensible”? But I know the answer: on Planet Beltway. ~Paul Krugman, The New York Times (sorry, NYT Select)

“Sensible,” like another euphemism in Washingtonese, “responsible,” is a word that can cover all manner of sins.  Typically it means that you accommodate yourself to the prevailing wisdom of the establishment, even when that view has ceased to be conventional wisdom everywhere else (normally because it has been shown to be horribly wrong), and do not turn on the establishment when times get tough.  Sensible men are, as Francis Urquhart might say, “sound men,” who will follow wherever they’re led.  Normally it is people like Francis Urquhart who put a high premium of this sort of “sensibility,” because it is useful to their scheming and not because it has any relationship to common sense.  People who say Joe Lieberman is “sensible” are probably likewise up to no good, but I couldn’t possibly comment.