Basically zero. The DEA Administrator is a Trump appointee. If for some reason he decides to fight it, he'd be gone immediately. They might try to slow-walk it

Basically zero. The DEA Administrator is a Trump appointee. If for some reason he decides to fight it, he'd be gone immediately. They might try to slow-walk it, but there's really no point. This isn't a fight anybody wants to win any more. If it destroys some fiefdoms within the DEA, nobody above them is going to care.