Gregg Phillips has mentioned that he (and some others??dunno) devised a method of tracking phones - used in 2000 mules, iirc - that can track the whereabouts of every illegal who has a phone. Will make it much easier to deport them.
True, but my idea is to prevent them from actually attempting to register and vote. The idea should be printed in Spanish on pieces of paper, scattered about, posted on forums, etc... and just generally seeded around. Spread the FEAR.