Sounds good, but your Crazy Libertarian Governor sees a path for danger: someone could easily use this as an excuse for discrimination. As, well, any government-imposed standard that uses fallible and not always objective humans in the process.
I propose an amendment:
1. Anyone applying for the substitute teacher position (including parents of the schoolchildren) must undergo a mandatory background check in order to be eligible for it.
2. Background check includes past criminal offences and mental health check.
3. Local school district education boards and police departments/sheriff offices are responsible for conducting the checks.
4. If a substitute teacher fails the background check it must be for a legitimate reason; not their gender, race, ethnicity, religion, sexual orientation, or similar discrimination.
I can't think of any other concerns, but one may come to me. If any one else has any that would be a good thing to voice--it's what debates are for, really: the why and the why not.