The Trump administration is exhausting every avenue to maintain law and order and protect citizens. The federal government could use the cooperation of local authorities. In cases where jurisdictions deliberately shield dangerous criminal aliens from facing consequences from Immigration and Customs Enforcement and other agencies, they will face repercussions from the federal government.
Sanctuary policies are legal measures that make communities safer by fostering trust between immigrant communities and local law enforcement. The federal government cannot legally coerce local authorities to use their resources for federal immigration enforcement, and attempts to withhold funding represent unconstitutional overreach that violates principles of federalism.