I'm a legal immigrant. First generation American here... My family moved here from Brazil when I was 11 years old. They did everything right. Admittedly, we had a slightly easier time because my mother is an American citizen. But I (and my brothers) all had to be naturalized. My dad still has a green card. I think at this point he figures he's too old to go through the whole process anyways.
In any case. One of the things that pisses me off to no end is people cheating the system. And immigration is no different. I seriously believe we need a four step program to get illegal immigrants out of this country.
Step one is to build the damn wall. Is it going to be expensive? You bet. Is it worth it? Hell yes. We have to stop the tide of illegals coming into this country for a handout.
Step two is a voluntary self-deportation. Why would they voluntarily self-deport? Because that's the only way they'll ever be allowed back into this country. *IF* they return to their country of origin, then they may get in line to enter the country legally. During this step, if you are not a legal immigrant or citizen, you CANNOT collect a single benefit. No food stamps. No section 8. No TANF. NOTHING. This would be at most a three month window.
Step three is the last phase during which they may re-enter the country. This is the cutoff phase. All employers are mandated to use e-verify to ensure their employees are in the country legally. If someone is not in this country legally, then employers may not deduct their wages from their taxes. This *should* eliminate the vast majority of those working illegally. Combined with the cutoff of benefits, this should eliminate the majority of the draw for those in the country illegally. Again, this would at most be a three month window.
Step four is the involuntary phase. If you are in this country illegally, and you are caught, then you are automatically deported back to your country of origin. There is no appeal, no delay, nothing. You're bussed to the border, shoved out the gate, and it's slammed behind you. Permanently. If you are deported during phase four, you may never re-enter this country. No temporary visas, no work visas, nothing. You are permanently persona non grata. Have family here in the US? Too bad. Should have left during the voluntary phases. There is no appeal, no waiver. If you apply for a visa, it is summarily denied without further review.
Basically put, it's a matter of eliminating the reward, and increasing the risk. At most, you've got six months to get your ass back across the border if you ever want the opportunity to re-enter the US (hence the importance of the wall as step 1).