Logistics. Practicality. 10,000,000 illegal immigrants. Let's say we will deport all of them over the next 10 years, assuming no replacement illegals of that period and they all politely declined to re-enter the country. That's over 2700 deported each day, including weekends. If we as a nation were really really enthusiastic about the task, and citizens readily turned illegals in, maybe we could do it. But we aren't and we can't.
All we need to do is cut them off from the Great American Mammary Gland, and they will go home all by themselves.
/1/ Enforce the Simpson-Mazzoli law, and go after buisinesses who hire illegals. (That is against the law, you might not know.)
/2/ No driver's licenses, period.
/3/ No tuition, no free education, period. (Can we get that in Mexico? NO!)
/4/ No free medical other than emergency, followed by a trip to the border for recovery in their home country.
/5/ No welfare, food stamps, housing assistance, period.
/6/ Change the current incorrect interpretation of the 14th Amd, which has led to the "anchor baby" situation, and chain-immigration under current "family reuinfication" laws, when the anchor baby reaches 18 years old.
Do the above, and there will be no need to "round up" 10-20 million illegals.
Give any form of amnesty to the current illegals, and get ready for 20 million more illegals in the next few years.
Tell you what. I'll bet that if we just started actively pursuing those on the lamb from deportation orders. And sent them back, testing the streamlined provisions in the realID bill. You would see such a shockwave many would pack it on on their own.
Should we experience the $20 tomato we are always hearing about, we simply reel in the deportations.