Looking at the info I've seen;
Since 9/11 most interior enforcement has been pulled with funds going to the border.
On the border, since 2001, six million have been caught. Of these six million, 400 thousand criminals/terroists have been screened out with the remianing non-criminals given a court date for a deportation hearing.
Most given a court date, don't show up. These, along with the others that sneak accross the border and don't get caught, become our illegal aliens probably to the tune of about 6 million additional since 2001.
Here in Nashville, they won't even arrest illegals short of felonies....maybe not even for class D-F felonies even.
The cops I know claim INS won't pick them up and they don't want to be stuck with them.