The definition of "tribe" is very flexible, at least as how it applies to human moral sentiments. I'm talking about psychological tribes, not literal ones (hence the slightly awkward phrasing in the passage of mine you quoted)

I'm talking about psychological tribes too. That is where politics finds it's primary home. To the extent that families and friendship groups act like tribes, they too have politics. As do offices.

As for laws, well, that's slightly more complex, made more so when our inter-tribe and within-tribe moral systems get somewhat blurred by circumstances.