No, Virginia, we can’t arrest illegal aliens

From the You’ve-Got-To-Be-Kidding-Me Department, if you’re an illegal alien, get thee to Virginia!
Apparently, so long as you’re not commiting a felony, you won’t get detained and possibly deported. No state law “to make arrests solely on the basis of a person’s immigration status”? Is this a Twilight Zone episode? Is Alan Funt hiding in the bushes somewhere with the camera? Do not law enforcement officers make arrests based on federal law as well as state law? The state of Virginia may not do the prosecuting and deporting, but surely they should be doing the arresting, no?
“I’m sorry for the delay, Mr. Atta. Despite your expired visa, your paperwork for your radiation-materials transport van appears to be in order. Drive safely, and have a nice day.”
Why don’t we just give up right now and hand over the nuclear bomb the jihadists want to wipe us out with, complete with AAA road maps so they can miss the construction on their way to the District?