Sanctuary cities under threat by Donald Trump
22 December 2016 Last updated at 00:22 GMT
If President-elect Trump wants to keep his promise to deport millions of undocumented immigrants he will need the help of local law enforcement.
But more than half of all undocumented residents live in so-called "sanctuary cities" - local jurisdictions that have vowed not to co-operate with federal immigration policies that seek to deport non-violent criminals.
Trump has called for a federal funding cut for those municipalities that refuse to hand over their undocumented residents and said he will focus on deporting criminals first.
The BBC went to Santa Fe, New Mexico, where Mayor Javier Gonzales says he will continue to provide a safe haven for peaceful immigrants.
Produced by the BBC's Franz Strasser.