Most people around here don't care much about politics. Politicians are perceived as liars and hypocrites while elections consist of choosing the best among the worst. I always felt Star Trek and sci-fi in general (especially futuristic ones) stood above current political situations, labels and squabbles. In the sense, that in those sci-fi features, in the far future, the world would be completely different than it is now (post apocalyptic or no freedom, or no water, alien or tyranny taking over, living on Mars, etc). For Star Trek, the invention of replicators, transporters, holodecks and interstellar travel. With replicators food hunger was eliminated on earth. And we can imagine (outside of canon) a completely different world for humanity. Less materialistic world since everybody would eventually have access to replicators. Meeting alien people and civilizations (hostile or not) unifying humans in some matter. In a us vs rest of the universe way (the us is americanized of course, since Star Trek is an American production).
All this to say that in Star Trek and many futuristic Sci-fi the world would be far beyond current political labels and positions and other new ones would be created, because of different challenges/technology/aliens, in our cases with the peril of exploring space with evil aliens and dangers facing us. In Star Trek, an action-adventure TV show, we also meet good aliens, allies and explore the wonders of the universe but in general we're facing evil aliens and facing the danger of space exploration. It's an us (humans) vs the universe thing.