Correct, they'd collect benefits, engage in the drug trade (or other black market/criminal activities), and other activities (ever offer a bum a chance to work instead of take a handout?) that they prefer to hard work like construction.
If there are 20 jobs, and you have 25 citizens who want work, and 2 of the 20 jobs are being held by non-citizens, how does that help the 7 unemployed citizens?
The number of jobs is not fixed, it is relative to the wages offered and the opportunity costs facing those available for employment. We have too high of a minimum wage and too large an entitlement system to reduce joblessness. Those legal problems create unemployment, not the number of people that exists at any one time.
No, we have too few jobs for the number of people wanting work. Hate to break it to you, but there are LOTS of US citizens that want work, and are not real picky. I know a number of guys in construction who are taking anything they can get to keep going. And I know at least 2 who have given up and are trying to find employment outside of construction.
The folks who have lost their jobs over the last 5 years didn’t lose them to welfare. And many are not sitting on their butts, talking on Obamaphones...