I don't think he thinks that at all.
He's basically saying the truth of the matter while the people getting mad on either side believe the truth doesn't matter. Only defeating the evil side at all costs.
It's the slippery slope of increasing tribal politics. The Republicans started it and went all in on it and now we're in a spot where sanity, truth, and logic doesn't matter. Just one side trying to turn to fascism and the other side trying to defeat fascism.
We and Stewart know trump is a traitor and even if Biden has full blown dementia he'd be a far better candidate than trump. Maybe Stewart gets to that or maybe he feels it just doesn't make good entertaining TV to do that. I tend to think he's waiting until the criminal trials get going to really get into it.
A question I have is how have the Democrats not cultivated a better candidate than an 80 year old for this election? Biden himself said he planned to be a one term president before the last election. He knew then he was a stop gap to defeat trump. He's an absolutely terrible candidate to be running at his age and that's just a fact. The way Stewart ended that first show told me he's disappointed the Democrats didn't do better to ensure the savior of the republic isn't an 80 yr old looking older and more senile by the day.