These folks sounds as though they cancel out in terms of burden vs benefit. We do need an avenue for immigrants to become legal, especially folks like these who wish to work hard. Some 90 yrs ago, all 4 of my grandparents, some with family members, made it to this country. Were they legal at the time - or not? I don't really know. They all became naturalized, worked very hard, lived with very little. Only my maternal grandmother learned passable English. My point? I don't know. We need some avenue for hard working immigrants to become legal if they aren't. Without draining our system. Or leave. What we have now doesn't seem to be working, but for most of us, at one time or another, our families were immigrants here. Maybe we don't need as many now, but I'd rather see a hard working, bargain hunting family legalized than the leftie professors granted visas to come and spread hate here, like the Yale professor who thinks 9-11 was the US' fault (searching for link).
The "avenue" you seek already exist, the illegals are just line jumpers.
I have friends and relatives who came to the U.S. legally, they REALLY resent the illegal invaders.