Since he left 'The Daily Show' behind, Jon Stewart's gone out of his way to keep himself busy - and when he turns up on the likes of 'Late Show', it's always with good reason.

It might simply be because he's got an issue he wants to address, or because he's got some good jokes on what's going on in the world, but his most recent appearance on 'Late Show' is different. Early last week, Stewart appeared at the US Senate and gave an impassioned speech regarding funding for the health fund for the first responders to 9/11.

These were the firemen, the paramedics and the police who were first on the scene on September 11th who helped survivors and, as a result, suffered health complications and diseases of their own. Stewart's been a vocal advocate for the work that they do, and appeared before the US Senate to try and ensure that the fund is approved again. As you'd expect with US politics, the whole thing is mired in bullsh*t, and Stewart made his feelings known in that speech.

Anyway, after that speech went viral, US Senate majority leader Mitch McConnell did the rounds on Fox and said that Stewart was "bent out of shape" about the whole thing, and that they'd eventually get around to taking care of it. So, what does Jon Stewart do? Rather than just respond to it, Stewart appears from beneath Stephen Colbert's desk and launches into a five-minute explanation as to what he's after, why it's worth Mitch McConnell meeting these responders, and lobs in a few jokes in the mix.

Take a look. Also, yes, we checked - Jon Batiste and the band were playing the Lost Woods music from 'Legend of Zelda: Ocarina of Time' at the start.