You're doing a thing here where you're equating "Democrat" with "liberal". That's less true than people think today, but it wasn't even a little bit true in Vonnegut's heyday. It isn't perfectly accurate to say we had four political parties in the 1960s (liberal and conservative Democrats, liberal and conservative Republicans) but it's not far off. The ideological sort picked up in earnest in the mid 1970s, and wasn't a dominant force in politics until the election of Reagan. Prior to Reagan, the Republican party platform was open to abortion!

Chicago under Daley (and long before) was deeply segregated (it still is). But Daley's was a conservative government.