Some have, yes. And some police chiefs have made quite clear that they will enforce any and all gun-grabs. The vast majority have said nothing at all. Not in public, anyway. I can't say that I blame them ... but I am grateful for those who have said they will tell Fedzilla to GFO.
What I am far more interested in is what the rank-and file agents and officers will do. Some will say GFY (and actively resist), some will get the blue-flu, some will enthusiastically carry out the orders of The Emperor. This applies at all levels. I think we would be foolish to under-estimate the percentage of patriots in Federal agencies, and foolish to overestimate the percentage of patriots in state and local agencies.
I think you have missed the most important type, the Fed or Local cop that finds out his neighbor buddy is going to be raided on trumped up charges and makes a little phone call. One guy like that can counter a 100 man raiding force....and if it's just to arrange an escape there's not much risk to the guy making it more likely he'll do it.
The fact that we work amongst them and they live amongst us is a element that needs to be taken into account.