What sort of insane reasoning arrives at this argument:

"We have refused to enforce immigration laws for a long time and by our own actions have created communities full of people who fear they may be subject to deportation for violating those very laws.  Therefore we can not be asked to enforce immigration laws because we will not be able to police our communities full of people who fear they may be subject to deportation if they talk to the police."

The Feds need to do more than turn off the cash to these cities.  They need to bring the politicians exploiting this situation up on charges.