Blair seems vulnerable. If he falls the left will use the fall to attack Bush, and damn well may succeed in ousting him(at least rendering Bush impotent). Interesting times! By the way let these leftist attacks be a lesson to those who confidently assert that conservatives are winning. The left is extremely entrenched(since WWI) and very very powerful. There is a long long road ahead and probably even actual fighting.
I suspect that Bush & Blair still have some cards to play that they are carefully holding back. Probably something less than 1% of the classified intelligence that they have on Iraq, on their SUPPLIERS (i.e., France, Germany, Russia & China), and on their SUPPORTERS (Chirac, Schroder, various protestors/useful idiots) has so far been made public. There could be some accutely embarrassing information that could be released when and if needed.
There will be multiple political careers, political parties, regimes, and alliances as collateral damage before this is all over.