by blaisdell » Tue Mar 27, 2012 4:49 pm
For the same reason the local police don't investigate and arrest tax evaders. It is not their job. It wastes their time and keeps them from doing their job.
The federal government has exclusive jurisdiction over immigration, and it should not ask states to do its job, unless it is willing to fund it. Further, being an unauthorized alien is not a felony. It is a civil matter, like failing to renew your license plates.
Many countries have one national police force, but we have 159 federal, 50 state, and 73000 local ones.
They can't be doing the other department's jobs or we'll have chaos.