Arthur Hiller, in tackling the public school system, was trying to make a biting film satire ala Network, and The Hospital. He ends up with so so success.
Nolte plays burnt out teacher at inner city school who's convinced he can no longer make a difference. Nick's fellow teachers ( Judd Hirsch, Lee Grant ) are too embroiled in office politics and strategizing an impending strike, to even remotely care about educating our youth.
Nolte finds a renewed calling though two students who show potential. One, a surprise, is the main bully of the school, played by Daniel-San himself, Ralph Macchio, who only month's before in the Karate Kid, played a weakling dweeb getting his ass handed to him by the Kobra Kai.
In this movie, Macchio, is supposedly the epitome of youth rebellion, talking smack to his superiors, prompting terror in his fellow cowering classmates, pulling fire alarms, all the while dressed in a fedora and trench coat
Nolte's renewed idealism, gets tested as he votes not to go on strike, and his fellow faculty play hardball by blackmailing him with rumors of teacher / student illicit relations.
Does Nolte stand by his ideals, or tow the company line.? Hiller tries to hammer this theme home, and at the same time by featuring insane outrageousness, by having lame stuff happen, such as an escaped mental patient showing up, unvetted, as new substitute ; having faculty whine sessions, years before Office Space made it hip, and worst of all, having the lovely Jobeth Williams, embarrass herself by going topless in a school hallway, as a symbol of fighting the system. Not sure how running around nekid helps the kids learn. But it sure made a few of them pay attention for the first time.