The portrait of Roger Ailes, the late, disgraced Fox News chief, that emerges in the meticulous and highly watchable (if one-sided) documentary “Divide and Conquer: The Story of Roger Ailes” is of a power-hungry, paranoid serial sexual harasser and friendless bully, a man who purchased a small-town newspaper in Putnam County, New York — where his weekend home was — just so he could shape coverage of hyperlocal issues.

Alexis Bloom’s documentary is also a story of incredible ego. In one anecdote, told by Warren Cooper and Karen Kessler of Evergreen Partners, the crisis management firm brought in to handle allegations of sexual impropriety against the Fox News CEO, Ailes and his wife, Beth, were told that it would be better to settle, rather than fight the charges. According to Kessler, Beth jumped up from chair and angrily said, “We will never settle this case. You need to understand something: Roger is more important than America.”

It’s a telling moment in a film that has many of them.

Also appearing on camera are the actor Austin Pendleton, a childhood friend of Ailes’s, former Fox News host Glenn Beck and former Fox News journalist Alisyn Camerota, who accused Ailes of sexual harassment. These and other interview subjects offer insights not just into Ailes’s career — and his prescient understanding of the importance of media in shaping opinion through fear and other emotions — but also into his psyche. Ailes himself, a hemophiliac since childhood, was a deeply fearful and distrustful person.

That’s liable to make you more sad than angry. Ultimately, “Divide and Conquer” offers useful lessons — and maybe even a little hope — for people on both sides of the national divide, about just how we came to this terrible, but not irreversible, place.

Unrated. At Landmark’s E Street Cinema. Contains some crude and sexual language. 107 minutes.