The Mexicans are coming to work for Americans for better futures. The palestinian terrorists are coming to Iraq kill Americans out of religious/idealogical hatred. Those who don't understand the significant difference have forgotten the meaning of September 11th.
Of course you are making the assumption that, out of the 400,000+ people that cross our southern border illegally every year, not one single person is a terrorist.
BTW, I've got some plots of land on the moon to sell you.