"Minimum standard for teachers" is just a tweaking of the parameters in the system by which the NEA defends its guild interests: the really corrupting, hidden monopoly which has destroyed American elementary and secondary education, the teachers colleges.
Breaking that monopoly with "freedom to teach" laws which allow anyone with a bachelor's degree from an accredited institution and a good GPA (say 3.3 or better) to teach grades 4-12 in their own major field is the only real way forward. Once that was in place, raising teacher salaries would actually help education. Without "freedom to teach" legislation additional education spending is money down a rat-hole.
I'm with you in trying to break the stranglehold of the teachers' unions on the educational system but give up the rampart of minimal standards showing teachers competency and you will have NO standards at all except paying union dues to NEA or AFT. And you can bet your ass that you will regret that!