Regarding the question of illegals paying taxes:
"The fact that illegal immigrants pay taxes at all will come as news to many Americans. A stunning two-thirds of illegal immigrants pay Medicare, Social Security and personal income taxes.
One might have imagined that those fearing deportation or confronting the prospect of paying for their safety net through their own meager wages would take a pass on the IRS' scheme. Not so. Close to 8 million of the 12 million or so illegal aliens in the country today file personal income taxes using these numbers, contributing billions to federal coffers.
What's more, aliens who are not self-employed have Social Security and Medicare taxes automatically withheld from their paychecks. Since undocumented workers have only fake numbers, they'll never be able to collect the benefits these taxes are meant to pay for. Last year, the revenues from these fake numbers — that the Social Security administration stashes in the “earnings suspense file” — added up to 10 percent of the Social Security surplus. The file is growing, on average, by more than $50 billion a year."
http://www.reason.org/commentaries/dalmia_20060501.shtml