Not only did he call the Iraq war a failure, but when Jeb Bush insisted his brother kept the country safe, Trump pointed out that the [September 11th] attack happened on Bush’s watch, and that Bush lied about the existence of weapons of mass destruction, and then returned to the point again. This is one of the deepest heresies in Republican politics. Republicans invoke Bush’s response to the 9/11 attacks, but they must discuss his record on terrorism as if he took office only after the attacks. The copious evidence that the administration received, and ignored, extensive warnings of a forthcoming attack has never pierced the Republican bubble.
— New York Magazine’s Jonathan Chait (In most heretical Republican “debate” yet, Trump goes after George W. Bush… again and again).