I'm not sure I understand what you meant to say here. I have never been asked for my birth certificate whan interviewing for a job, not only that, but it would create a problem for naturalized American citizens whose birth certificate is from a different nation.
There's also the fact that birth certificates offer nothing in the way of proof as to whether the individual presenting it as proof it is actually the person in the document. They are also very easy to counterfit.
I am all the time when applying to work in schools. The easiest thing to use is that birth certificate. If the person is a naturalized citizen, they can bring along proof of citizenship. Again, no big deal.
There's also the fact that birth certificates offer nothing in the way of proof as to whether the individual presenting it as proof it is actually the person in the document. They are also very easy to counterfit.
Then, again, you do what I have to do all the time. I also have a picture ID (driver's license, passport, college ID, etc.) for proof. Anyone who wants to buy a beer or a cigarette has to have that for proof.
It's a small price to pay to get the criminals who are in the country illegally deported. (And anyone here illegally is a criminal). And, anyone who is here illegally or not proud enough of their citizenship to prove it should leave the country immediately.
We don't have any need for the immigrant population right now. What we do need is to secure the borders and stabilize the population. There are plenty of people to do the work...aging and retiring baby boomers who lost their retirement money in the stock market fiasco will provide a wonderful labor source.