"Candidate for elective public office in the state of Missouri" could be read either as can't be a candidate on the ballot in Missouri or can't be a candidate for a state position. It depends on if it means [candidate for public office] in Missouri or candidate for [public office in Missouri].
I don't like how laws are always written very formally like that, I feel like English (or any language tbh) is able to be misinterpreted easily enough as is, and the stilted way it's used in legal speak just leads to questions and misunderstandings like this. I'd much rather they be written as plainly as is possible and in ways that attempted to remove ambiguity instead of add it, though a lot of the time that's the point I imagine lol.
It's crazy how many articles I've seen that just casually imply or outright say he did it.