It's not a matter of if, it's a matter of when, imo.
We can either attack him now, on our terms, or later, on his.
I for one don't like the idea of trying to 'contain' him... we 'contained' states throughout the cold war and all we did was prolong the misery for the people while simultaneously letting the problem get too big to deal with, to the point that we're effectively blackmailed.
Well, yes, I suppose, if he survives. But something could happen to him.
Exactly the President's point, although why some (notably Leftists/Dems) refuse to get it is beyond me. Politics aside, they and their families are just as vulnerable as the rest of us to use of WMD by nutcases like Saddam and any radical Islamists he decides to use as agents.