Multiple State sue Trump's Administration For Pulling of Funds

So why are the states doing the federal government? What is the legal argument that is being used?

Group of Cities, Counties Sue Over Trump’s Bid to End Sanctuaries https://link.theepochtimes.com/mkt_app/us/group-of-cities-counties-sue-over-trumps-bid-to-end-sanctuaries-5806867?utm_source=andshare