I think you're spot on about politics being akin to religion. People fall back on their politics as a source of identity, a defining purpose, a way to demarcate their in-group and provide them with an out-group to hate. The cognitive distortions that are happily taken to justify all kinds of inconsistent beliefs, the way it organizes people socially and interpersonally, the visions of one day being rewarded for all their efforts with their faith's version of a utopia... yeah, I think the parallels are there in many ways.