How to stop cities from promoting illegal immigration

The Department of Homeland Security conducted an immigration raid in New Haven. New Haven claims the raid occurred because the city intends to give identification cards to illegal aliens.

I don't know if the raid was done to retaliate against New Haven's pro-illegal immigration policy, but it should have been. Many cities enact laws designed to help illegal immigrants overcome federal immigration laws. If Homeland security had an announced policy of having increased raids against these cities, then the cities would quickly kill their pro-illegals laws.