Same as before. First they will sympathize for a few days then they will want to analyze the "cause" of the attacks which will always be Bush's fault.
Here's a DU response:
"Yes, Blair, "barbaric," just like the daisy-cutter bombs you and yours dropped on innocent people in Iraq. As Richard Clark had predicted, your preemptive attack on Iraq--and your little buddy's, the Chimp--has brought more terror on the world, not less. Wake the hell up. You brought this on all of us."