The footage of Jon Stewart speaking truth to power on June 11th captured our attention right alongside everyone else. The argument—Americans should cover first responder medical costs related to Ground Zero service—is so airtight it’s hard to believe it needs to be made. Unfortunately, it does. An estimated 95,000 people suffer from 9/11 related illnesses. Without action, the September 11th Victim Compensation Fund will expire at the end of 2020.

What makes Stewart’s testimony remarkable goes beyond the solid argument and the words he so effectively uses. We watched, shared and then watched again because of the raw immediacy of his delivery: it’s authentic, and that’s not an adjective we use lightly. (The thing about authenticity is that the more it’s been talked about, the harder it’s been to find.)

So what exactly sets Stewart’s testimony apart?  What makes it “authentic?” For American celebrities, it’s a rite of passage to lend “name and likeness” to a cause or two.  Yet only a few stick around when the cameras move on. That’s not what Stewart is doing. The way he adeptly pulls from stats (official FDNY response time to 9/11 was five seconds) and detailed personal stories of first responders reveals the depth of his connection. This is not political posturing; it’s personal. And that’s why the tears he shed and the anger he showed hit us so hard.