Seems to me the State of Florida does have the power to arrest a "Federal" criminal and hold the criminal until the Feds arrive...Sounds like a cop-out to me...
Their numbers would be doubled and subtracted from the reported population of the area. So when reapportionment, government funding and other goodies come around, areas with illegal immigrants would be penalized rather than rewarded. Big states like California, Illinois, New York, Texas and Flordia would probably lose congressional seats. Rural backwaters like Oklahoma, Mississippi and Indiana would probably gain seats.
Once illegal immigrant pandering ceases to be fashionable, so would illegal immigration.
Just curious, why exactly does illegal immigration concern you?