Alot of it is the same illegals going back and forth. They go home for Christmas, family reasons, etc, then head back here when they are done. So we are counting the same people over and over and over and over...
Might be a lot of that, but the huge number of border crossers still makes the estimates of illegals in the country a pretty sad joke.
I see you have a background in sigint. So run these numbers in your head: Do you think the international prepaid calling card business can support itself entirely on legal and officially estimated illegals? Or do you think our government does not want us to see the enormity of the problem?
Anyone who can fog a mirror can get a credit card and, hence, a postpaid account with a wireless MNO. Why do we have a HUGE growth in prepaid wireless? Not young kids - they are on their parents' family postpaid accounts.
Based on some VERY basic traffic analysis, I bet our government has a pretty good handle on the actual number of illegals, and it's a LOT more than 20M.