A fundamental idea in Democracy is that in any decision process, opposing viewpoints should be argued and the decision makers (voters) ultimately make their decisions based on the relative merits of the arguments as well as their personal interests and values. This isn't (necessarily) the same thing as tribalism. In tribalism, the decision process is short circuited so that arguments, value systems, and even one's own self-interest aren't taken into consideration. After a decision-maker has aligned themselves with a particular tribe, the arguments and relative merits of policies may no longer be looked at because they just care that whatever positions "their" tribe has made "win". In fact, they may not have any notion of how their tribe even came to their decision in the first place or any idea how that decision will ultimately effect them.