The California Police Chiefs Association does well in not supporting the proposal to augment immigration officers with local police.
Actually our local law enforcement officers already work with immigration in many cooperative ways. Law enforcement officers will usually lend a hand in assisting other federal officers in their duties, just as they in turn help police.
Inter-agency cooperation is well known and appreciated in the law enforcement community, especially in the Imperial Valley. To make it mandatory will be counterproductive as well as tax our overburdened law enforcement officers.
Our government is also well known to mandate things without paying for it. I would suspect that the burden of these mandates that are proposed will still be carried on the backs of local governments, not the federal government.