Brandon Fuller politely suggests cities should take immigration policy into their own hands:
One idea we’ve discussed at the Urbanization Project is the notion of a city-based visa. Not all cities welcome additional immigration, but perhaps those that do could sponsor visa holders. The visa could be temporary and renewable, with a path to permanent residency and eventually citizenship. Visa holders would be free to bring their immediate family members with them.
Presumably, the sponsoring cities would have to adequately address some of the primary concerns of immigration opponents, ensuring that visa holders do not receive means-tested transfers from the federal government, commit crimes, or disappear into non-participating cities. A participating city could choose to sponsor undocumented immigrants, provided the city is willing to take on the responsibility of making them legal residents and eventually citizens.