Attacks by individual suicide bombers targeting public places (like malls) are almost impossible to prevent unless law enforcement gets very lucky. On the other hand, the terrorists probably know that they are damaging their own cause by this tactic. Imagine the backlash against Arabs & Muslims in this country if suicide bombing is tried here, even on a small scale! They will either leave or be lynched.
That depends on the magnitude of the attack(s) and government spin. IMO, it will take a LOT of small scale attacks or one massive (50,000+ dead) to wake enough sheeple from their complacent slumber. Come to think of it, it might indeed take 100,000+ dead.