This format works best it focuses on a single, discrete entity for mockery, whether it’s as nebulous as “cable news” or “the Republicans” or as specific as Sarah Palin. Today’s political landscape mostly lacks foes of that caliber. The 2008 election deprived Stewart of his greatest target, and George W. Bush’s replacement didn’t help much, either. Liberal comedians haven’t been afraid to mock Democratic presidents before: Jay Leno, according to one study, told 4,607 jokes about Bill Clinton during his reign on the The Tonight Show. Liberals then caricatured Bush as unintelligent and hapless. His tendency for poorly worded phrases—“Is our children learning?”—and ill-conceived policy decisions like invading Iraq made it an easy sell.

The dearth of targets goes beyond the White House. Also gone are the Michele Bachmanns, Herman Cains, and Glenn Becks of yesteryear; jokes about John Boehner’s skin tone and Mitch McConnell’s droopy jowls only go so far these days. Even Fox News became so over-the-top in the Obama era that it’s almost beyond parody. You could see it in one of the segments before Stewart’s announcement last night, when a Fox News host earnestly said in a clip that the President of the United States “puts the Koran first and the Constitution second” when fighting ISIS.

Liberalism hasn’t won, of course—it just ran out of easy targets. The Koch brothers now loom large as liberal adversaries, but they rarely give interviews and certainly don’t make clip-worthy gaffes. The GOP primary field for 2016 runs a dull gamut from Jeb Bush and Scott Walker to Rand Paul and Marco Rubio—hardly an inherently comedic set of candidates. Maybe this was a self-fulfilling prophecy. Establishment Republicans set out to purge the more extreme Tea Party members during the 2014 primaries, leaving fewer candidates like Todd Akin or Christine O’Donnell with easily mockable gaffes on “legitimate rape” or witchcraft. Their efforts largely succeeded, to both their electoral success and Stewart’s loss.

News cycles also became considerably darker in recent months, and the toll became apparent. In his tribute after the Charlie Hebdo attacks last month, Stewart called the cartoonists’ deaths “a stark reminder that, for the most part, the legislators and journalists and institutions that we jab and ridicule are not, in any way, the enemy.” In his first episode after Ferguson last August, Stewart doubled his opening segment’s length to excoriate Fox’s coverage of the unrest. As he piled one absurd clip after another with a prizefighters’ staccato, his light tone gradually slipped away as he spoke about discrimination experienced by his own colleagues. “Race is there, and it’s a constant,” he said in the end of the segment, all levity gone. “You’re tired of hearing about it? Imagine how fucking exhausting it is living it.” Everybody clapped. Nobody laughed. Stewart looked drained.