The only way people are going to get behind the team is through results. Sadly, despite what anyone can say or do on here, that is the only measure.
I think its right to point out certain mitigating circumstances in defence of the manager. We didn't get a pre-season, and our early season form did suffer because of that. We didn't meet expectations in the transfer market this summer, and failed to take advantage of our restored CL status. Those are valid mitigating circumstances, but as said a lot of our fanbase just won't care about that. It's the pressure that a United manager operates under. Results & performances are everything.
Nobody is going to get behind the manager and the team if they are not already there. Not unless we win a LOT of football matches. Fortunately, in my view anyway, the club still seem to be fully behind this so if anybody is not enjoying being a United fan for whatever reason, then this is going to be a long season for you.