"Sanctuary cities" - jurisdictions that refuse to assist federal government attempts to deport undocumented immigrants - have become a major focus of political conflict over immigration policy. The Trump administration's efforts to punish sanctuary jurisdictions have led to multiple legal battles over constitutional federalism.
The administration's crackdown on sanctuary jurisdictions has helped make federalism great again. It achieved this unintended outcome by generating a series of court decisions protecting state and local governments against federal coercion, and by leading many on the political left to take a more favorable view of judicial enforcement of constitutional limits on federal power.
This is the first academic article to attempt a comprehensive evaluation of the federalism issues at stake in the Trump-era litigation on sanctuary cities. The article assesses the three main sets of sanctuary cases that have arisen during the Trump administration: legal challenges to Trump's January 2017 executive order targeting sanctuary cities, challenges to the Justice Department's July 2017 policy of conditioning federal law enforcement grants on state and local government cooperation with efforts to deport undocumented immigrants, and the administration's lawsuit against California's "sanctuary state" law. So far, at least, all three have led to notable victories for advocates of constitutional limits on federal power.
The sanctuary litigation has also produced a noteworthy reversal of the usual ideological valence of judicial enforcement of federalism, with progressive "blue" jurisdictions relying on legal doctrines traditionally associated with the political right. Whether this helps trigger a more lasting shift in attitudes towards federalism remains to be seen.