Myths of illegal immigration...

...studies claiming some modest overall gain for the economy from immigration ($1 to $10 billion a year) have found that it is outweighed by the fiscal cost ($15 to $20 billion a year) to native taxpayers." - http://www.theamericanresistance.com/issues/economic_costs.html

Myth 1: Illegals take jobs American won't because Americans are too lazy.
Truth: Illegals artifically force down pay by taking a job for less money. We live in a capitalist society where supply and demand control price. Americans will take any job if the pay is high enough. Illegals will take the job at a much lower pay and therefor allows employers to offer less pay for a given job. This is the exact same practice as dumping which is illegal.

Myth 2: Illegals contribute more to the American economy than they take.
Truth: Illegals cost the US far more money than they contribute. Follow these links:

Economic costs of illegal immigration
Costs if illegal imigration