Nothing went wrong with Sanctuary Cities. They are working as designed.
It's just an unsustainable design of Globalist bleeding heart open border elite limousine liberals who have the luxury of spending Summers on Islands off the East Cost of the US., where they can isolate and insulate themselves from the consequences of their own policies.
Why would a suburban limousine liberal Dem summer-ing in Montauck, the Hamptons, Block Island, Martha's Vineyard, and Nantucket give a damn about what's happening where they are not?
NIMBY - to get a liberal to move on any problem, you have to put it in their backyard first. Otherwise, liberals are too damn isolated and insulated to give a turd about what happens to people who are not them.
Dems will be spurred into action when their urban supply of voters in the cities start raising a ruckus.
Keep sending those buses North.