If you’ve watched the final episodes of “The Late Show with Stephen Colbert,” you won’t have missed the sense that something monumental is ending. When Jimmy Kimmel, Jimmy Fallon, John Oliver and Seth Meyers appeared on the show, Colbert’s fellow late-night hosts joked — half-seriously — about who might be cancelled next. The consensus, of course, was that it would likely be Kimmel.  In a separate appearance, former “Late Show” host David Letterman expressed open frustration with CBS, suggesting the network failed to recognize the value of what it had. Letterman also jokingly expressed concern for Fallon and Kimmel, asking if they would be “all right” after Colbert’s departure. Colbert responded humorously about a ‘captive breeding program’ for the Jimmys.  Taken together, these moments point to a broader reality: The end of Colbert’s show unquestionably marks the end of an era. But what exactly is ending? Is this the death knell of American political satire? And if so, what does that mean for the future of ironic political commentary in the United States? What is …