As the politics outside its doors have led to increasingly cavernous divides, so have the politics inside at The Second City, where executives are coming and going, and where more than half the cast abruptly left a fiery but well-received e.t.c. show, some going public with their discontent and one suing another and alleging racial discrimination. Which may explain why the new mainstage show at Second City, “Dream Freaks Fall From Space,” feels like it’s been assembled by people who’ve had it up to here with politics and just want to goof around. In the continuing advancement of Second City as a source of insight about the world, this show is a step backward. Which doesn’t mean it’s a bad show. Just not a very ambitious one. ‘DREAM FREAKS FALL FROM SPACE’ Recommended When: Open run Where: Second City, 1616 N. Wells Tickets: @29- Info: (312) 337-3992; Running time: Two hours with intermission While “Dream Freaks” over all adapts the sensory bombardment techniques of recent revues at Piper’s Alley — a relentless, quicksilver pace, barely perceptible scene breaks accompanied by brief throbs of wake-up music, f-words galore — within the moment it tends to play old school. How old-school? The opening is literally a guy — Nate Varrone — sitting at drum set, rattling off one-liners about America and providing his own rim shots. Straight outta vaudeville. The likable writer-performers spend the whole show in white jumpsuits, something about how everything is a 21st-century dream by people in the year 80,085. But that gimmick doesn’t come up much, save for a funny little Lilith Fair song by the cast’s three women in gray wigs, celebrating (explicitly) how life improved for women after the patriarchy fell. More often, the cast and veteran Second City director Ryan Bernier evoke the past. Just as an earlier Second City generation softened tough-guy Chicago cops by putting them in a ballet (“Swine Lake”), these actors do the same with tough-guy Donald Trump. Remember how funny it was when Sam Richardson stripped to his undies and danced? Here’s another chunky guy doing the same. Some of the more grounded, character-driven scenes barely touch on