First, there is the larger effect on the sanctity of a legal system. If a guest ignores the law — and thereby often must keep breaking more laws — should citizens also have the right to similarly pick and choose which statutes they find worthy of honoring and which are too bothersome? Once it is deemed moral for the impoverished to cross a border without a passport, could not the same arguments of social justice be used for the poor of any status not to report earned income or even file a 1040 form?
Second, what is the effect of mass illegal immigration on impoverished U.S. citizens? Does anyone care? When 10 million to 15 million aliens are here illegally, where is the leverage for the American working poor to bargain with employers? If it is deemed ethical to grant in-state tuition discounts to illegal-immigrant students, is it equally ethical to charge three times as much for out-of-state, financially needy American students — whose federal government usually offers billions to subsidize state colleges and universities? If foreign nationals are afforded more entitlements, are there fewer for U.S. citizens?