At what point do you decide to go over your bosses head?
 

If your boss was doing a bad job or they were effecting the way you did your job, at what point do you think it would be ok to go over their head to their boss so that your job performance didnt suffer?

After there's so much DOCUMENTATION of the lower-level boss being a sh*t employee that the higher level boss would have no choice but to see your side, at the absolute earliest. Record every interaction so you can pass on the ones where boss sucks at bossing and save all emails At LEAST.