It has an alien species where the religious group has quotes that are directly from Carl Sagan (and they're have more of a philosophy than a religion, at least in most ways). It generally treats religion with more respect than Roddenberry did, in a "all religion has some good parts to it, but extremism is a problem" kind of way.

One of its major plot arcs is all about how democracies fall into fascism. I thought it was a bit heavy handed at the time, but now it feels too real.

Skirts around a pair of characters in a lesbian relationship, but like most shows at the time, it doesn't come right out and say it. They 100% banged one night, though.

It's also military science fiction. That always seems to invite right wingers who love the asthetic but ignore the themes. Same problem with Star Trek and Star Wars.