There were a few choices of articles to pick from, and I chose this one because President Trump's EO was made clear, that the Atlantic didn't have the report quite right.
The premise of The Atlantic’s argument claiming Trump’s order is forcing localities to enforce federal law is not particularly accurate. Rosemary Jenks, Director of Government Relations for NumbersUSA, says Trump’s order on sanctuary cities does not mandate state and local authorities to deport illegal immigrants. Rather, it mandates that state and local authorities not obstruct the Immigration and Customs Enforcement (ICE) agency’s job in deporting illegal immigrants. “The executive order doesn’t say they have to enforce federal immigration law, it just makes sure they don’t block federal immigration law,” Jenks told Breitbart Texas. “Local authorities are not authorized to deport illegal immigrants,” Jenks said. “The fact that local authorities can block communication with feds so no one can be deported. It’s absurd.”
Ordering the ICE Agency be allowed to do their job by locals not blocking the agency communicating with the Fed.. is not illegal So, there isn't any Constitutional infraction that I see if AG Sessions approaches it that way---it would be the local Police violating the Law!!!! Let ICE do their jobs!!!!
If he approached it that way, it's not coercion. He would simply be saying if your state's Police force is corrupt by breaking the Law, that he doesn't want to grant a loan to a state involved in illegal activity. Perfectly reasonable.