Yes. According to the Center for Immigration Studies.
Why? Enforcement of existing laws to weaken the strongest magnet for illegals: employment.
Says EM over at HA,
"The CIS researchers think that enforcement alone, even without tougher border security, could cut the number of illegal immigrants in half over the next five years. With a stronger border and even better scrutiny, that pace could accelerate even further."
Update: How we know immigration enforcement is working–part II. See-dubya explains.
