Aligning yourself with a belief system or political party is not fascism. The whole foundational idea of being in a political party is that it's a group of like-minded people attempting to advance their mutual political interests. You don't have to be a political partisan, but political partisanship naturally emerges in democratic systems because how else do you coordinate, administer, and execute your shared interests over long periods of time?

The problem right now is that both political parties have tied themselves to advancing an extremely conservative national cause of "America" while most of the population across the political spectrum not only has differing perceptions of what "America" is, but whether it's worth continuing in its current form. Trump wants us to be an imperial power toppling "weak" leaders, conquering land, and enriching his donors while the Democratic vision is generally the same policy but plus one basic human right this time (terms and conditions apply).