Jon Stewart finally explained at length why he is leaving The Daily Show.

He started by showing clips of reaction to his announcement from the right — mostly Fox News Channel, where Megyn Kelly is seen talking about how “nasty” Stewart got, with “no foothold in the facts.”

He challenged FNC to a Lie Off. “Your distortions and lack of fact foothold against mine.”

He presented a clip he called 50 Fox News Channel distortions and lies in a 6-second Vine and invited viewers to go to his show’s website to peruse more at their leisure.

Then he turned to Rush Limbaugh having said he, Stewart, has “poisoned the Republican brand.” “How do you poison a cyanide factory?” Stewart pondered.

“In their mind the opposite of bad isn’t good — the opposite of bad is conservative,” Stewart cautioned, telling viewers to stop pretending that any concessions to the right will sate the beast.

“Take it from someone who’s been watching what they do for a blessedly almost over 16 years or so. Their chronically angry war for ideological purity, where every aspect of live becomes a two-dimensional battle for America’s soul — it ages you. Even watching it is killing me.”