The worst lie that liberals tell about Bush's Middle East policy is that everything in Iraq might have turned out great if only we'd appointed "competent" people. This is a cornerstone of the "incompetence" meme regarding the Bush administration, one rooted in a (quite justified) outrage at the cronyism and stupidity of the current regime.
In the case of Iraq, however, this meme supports the dangeous illusion that the problem with the war was one of execution, rather than ideology and aim. Alas, not even the most competent administrators in the world could have made the postwar in Iraq succeed. This is why the invasion was, to paraphrase Talleyrand, "worse than a crime; it was a blunder." While the White House may be filled with knaves, in the case of Iraq, the knaves were also fools.