Why is local Sanctuary City "uncooperation" different than 2nd Amendment "uncooperation"

Attorney General Jeff Sessions yesterday intimated that federal funds were going to start being withheld from Cities and States that had passed "Sanctuary" legislation instructing their police and other local agencies not to cooperate with federal law enforcement efforts against illegal aliens within their jurisdictions.

There seems to be widespread approval of Session's action from the political right.

But I remember not so long ago that many on the political right were applauding the State and Local governments that were doing the same thing regarding the enforcement of federal laws concerning firearms, instructing their police and other local agencies not to cooperate with federal law enforcement efforts against gun ownership.

So, are we on the right now becoming that which we have so roundly criticized, because the guys we helped elect are now in power and doing it to those we have disagreement with?