As the long-time host of the Daily Show, Jon Stewart forged a relationship with both Washington insiders, and the greater American people. He is more than capable of successfully arguing his case to become a Supreme Court Justice before the Senate Judiciary Committee.
As a SCOTUS Justice, Mr. Stewart would be able to adjudicate fairly, and with an open mind. He's known to research any and every topic at length in order to speak knowledgeably, and without bias. In that regard, Mr. Stewart is as qualified to occupy a seat on the High Court, as any sitting judge.
Plus his opinions would be epic.