peopel of the village won't choose him as hokage remember madara??
they will choose naruto instead of him this will anger sasuke ,sasuke like madara did would want to kill the hokage (naruto)
Mark my words if nobody dies during this war and sasuke and naruto are still alive you never know with naruto
Madara before diying or during the battle will say to sasuke
''brat there is no way an uchiha will ever become hokage'' this words will brainwash sasuke's mind and later the words of
madara becomes true sasuke is back to his evil self