It's very much illegal at the federal level.
Which I think is a good thing, but many arguing this angle for marijuana legalization haven't fully considered the implications.
Nevertheless, it's not the current law as far as the courts are concerned, despite what the 10th amendment says. (I suspect the current SCOTUS wouldn't mind rectifying that, given the proper cases and opportunity.)
But in the current political climate, try saying the words "state's rights" without getting labeled a racist or extremist or anti-masker/vaxxer.
And why are his officers complaining that the truck is "light", and "what do you mean, that's all you got?"
Let's not pretend this is being done for any reason other than to enrich coffers.
1. Because his department (and possibly him specifically?) get a kickback from the federal agency on asset seizures.
2. To deny that he is simply pocketing the money for his department on his own authority.
Which it is technically accomplishing.