Try Googling.
BTW, we pinged you yesterday to join us in the thread about those kids killed by an illegal alien in Minnesota. I’m shocked you lacked the guts to participate in the discussion (yes, that’s sarcasm).
http://www.worldnetdaily.com/news/article.asp?ARTICLE_ID=55135
There are at least 5 million children of illegal aliens attending public schools in the U.S. each year. American schools spend an average of somewhat more than $8,000 per year per student to "educate" children who are fluent in English, and about 20% more for children who are not fluent in English. This works out to about 40 billion dollars a year for a very conservative estimate.
That number alone exceeds all of the taxes that are estimated as being paid by illegal aliens, and is only one of several major costs associated with their illegal presence here.
If you were really interested in the truth, you could estimate these many costs and few benefits for yourself. Since you are not, no amount of "proof" will convince you.
The share of immigrants and natives who are college graduates is about the same. Immigrants were once much more likely than natives to be college graduates.
The proportion of immigrant-headed households using at least one major welfare program is 33 percent, compared to 19 percent for native households.
The poverty rate for immigrants and their U.S.-born children (under 18) is 17 percent, nearly 50 percent higher than the rate for natives and their children.
34 percent of immigrants lack health insurance, compared to 13 percent of natives. Immigrants and their U.S.-born children account for 71 percent of the increase in the uninsured since 1989.
Immigrants make significant progress over time. But even those who have been here for 20 years are more likely to be in poverty, lack insurance, or use welfare than are natives.
The primary reason for the high rates of immigrant poverty, lack of health insurance, and welfare use is their low education levels, not their legal status or an unwillingness to work.