Many teachers work overtime for their classrooms and are not being payed for it. Teachers arrive before school starts and leave after the school day ends. Most teachers arrive at least an hour before the school day starts for students and leave at least an hour after the school day ends. If school districts paid teachers more, then they would have less teachers quitting due to burn out and lack of pay.  Having more teachers to fill classrooms means that the ratio of students per each teacher is decreased. 

If things stay the same, we lose a lot of teachers, which means schools will be shut down due to lack of educators. Instead of the average number of students in each classroom being 20-21 students, the new average will be 25-30 students in a classroom. Having that many students in one classroom will overwhelm teachers and will increase the number of students that are not learning or are struggling to learn.