BEFORE SEAN HANNITY, Glenn Beck, and even Rush Limbaugh, one loud-mouthed media personality rose above them all: Morton Downey Jr.

It was the late '80s, and The Morton Downey Jr. Show was the raging, spittle-spewing antithesis to the Phil Donahues and Sally Jessy Raphaels of the time, in which the chain-smoking Downey would welcome liberal guests (including lawyer Alan Dershowitz and Al Sharpton) and verbally rip them to shreds. Climbing right up into his guests' grills, he would scream his catchphrases ("Zip it!" and "Pablum-puking liberal!") directly into their faces as his rapt, cheering audience (often called "the Beast") gave the Nuremberg Rallies a run for their money.

At the time, I remember it being hilarious. And very difficult to take seriously. But while Downey and his lynch-mob audience didn't quite start the fire, the sparks he emitted set the stage for the glut of today's right-wing lying loudmouths, reality trash shows, and social media trolls.

And so Évocateur: The Morton Downey Jr. Movie gives you a lot to think about. It's a story of a man so obsessed with besting his famous father that he destroys himself. It's the story of America's bloodthirsty obsession with conflict. And it's a very effective history lesson in how the loudest voices can too easily sway those who aren't prepared to think for themselves.

It may not be the best documentary you'll see this year (and definitely not the cheeriest), but you'll be hard pressed to discover another film that so clearly connects the dots from Downey and his disenfranchised, voiceless viewers to the rise of reality TV and the Tea Party. It also reveals that while the loudest voice initially gets the most attention, eventually people just get tired of being screamed at.