This of course requires the MASSIVE assumption that formerly illegal aliens would all of sudden begin working above the table, dutifully paying their taxes.
That's one hell of an assumption, especially when you consider the huge numbers of illegal aliens that have no interest in obtaining citizenship:
Pew Study: Not All Immigrants Want Citizenship
The CBO is a calculator, nothing more. They'll spit out real numbers, but those figures are based on the assumptions provided by elected representatives.
Here's a better idea: End the nanny state entitlements, Obamacare, and all these welfare programs left over from the failed so called 'great society', and end the immoral practice of taxing a man's labor...and nobody will care who works in this country, citizen or otherwise.