The Islamists don't like him, and he doesn't them.
He's a real bad guy in a lot of ways, but in a War on Terrorism, invading Iraq represents a major loss of focus. He's any number of kinds of rat-bastard, but he isn't currently a terrorist.
When 41 wimped out last time, it was to keep the coalition together. I don't see a coalition forming in the first place this time. If we invade Iraq without Iraq doing something beyond borders first, we will be going in almost alone. Probably get a little symbolic support from a few of our staunchest allies (I can't see Great Britain not backing us short of an unprovoked first strike on the Netherlands) but the diplomacy is going to be bad. 41 wasn't concerned (to the point of blowing the chance to shut down Saddam completely) about the diplomacy because he's some kind of lefty peacnik, and I doubt that going it alone is a much better idea now than it was then.
And any strategy that calls for the Kurds doing anything is doomed - they don't have the MTV attention span, and haven't forgotten how it went down last time they put their lives on the line to help us.