The first question is, "Does an employee of the State of Missouri, one of its counties, or one of its municipalities have a duty to enforce Federal statutes?". Then, "Articulate the statutes that require that activity. Note that it's expressly forbidden in the State of Missouri."
After that the judge needs to be pressed on the hypocrisy of his position on state and federal marijuana laws.
There are a barrel of other arguments contrary to the judge's opinion.