I've played in a lot of country bands over the years, everything from hillbilly to rockabilly and i've never been hired for my politics. As far as that goes i've never been asked (in a musical setting) about my politics but once and that was by a BL putting together a band specifically to play rallies for a guy running for governor, and the subject came up in the audition by way of "keep your politics to yourself and play". Other than that it's always been about what i could do with the bass and would i show up on time prepared to play. I've also been hired based on someone i knew but it was always a fellow musicial type passing my number and a good reference to someone looking for a bass player.
I've seen the tribal approach to band building but mostly in P&W, and seriously deep metal bands where ads will stress that only true believers need apply, but this is the first ad i've ever seen where a pro player would also need to be a specific age as well as politically and philosophically aligned with the BL in order to land a country music job. I'm surprised there was no stipulation regards dress or overall "look" as well, but i guess that's so they won't scare off any prospects.
On a strictly personal note, i've played with all kinds of folks from all over the political and philosophical map and i've always focused on being a good bandmate who was there to do the best i could to put out a great musical product, but if some aligator mouthed bigot, racist, or whatever started in, i'd join right in and give them a taste of what it feels like to have some crass, vulgar A-hole denigrating them and their general outlook on life to their face rather than behind their back. So far i've been lucky and haven't started any fights or been fired for it, but as we continue to dig deeper into a tribal mentality where blind loyalty to a particular worldview dictates all our other choices, i'm sure that day is coming.