Nonpartisan. Though there are not really movements against this, just small nations that ban parties.

I will push back on your opinions, though. “Division” is not a moral or political quantity. It is not itself good nor bad. Trans people were universally oppressed for centuries. Now they have some protections. This is a consequence of struggle against transphobia, that struggle is inherently a division. There are transphobes and pro-trans people. The pro-trans group should win. For them to win we need to support them materially and in as effectively as possible, which means through organized work. Progress against oppression only occurs through division and struggle. And the best vehicles for this are organizations - basically parties or very similar apparatuses.

The two-party system is a symptom of deeper problems and they shouldn’t be summarized as division. The two-party system is really just a very effective way for the ruling class (business owners) to achieve their ends while still providing a venue for “the political”, often struggles and oppressions that they personally exacerbated. For example, some of the earliest institutional racism in what would become the US emerged due to worker solidarity and struggle. The ruling class decided to divide and conquer: they created a race-based system, defining a new class corresponding to “black”, who would be the most exploited, and exploiting everyone ekse skightly left. This is not theater, as the oppressed are facing actual oppression, but it is cynical: it’s really about profit maximization and controlling workers. The two-party system makes this kind of thing a constant endeavor, you can spend all of your time invested in struggles imposed by the ruling class and exemplified in the parties, and in doing so never focus on the underlying system that creates it. But of course not every oppression makes its way into this attempt at distraction, as when the oppression is bipartisan (no division in that case but still bad!). For example, both parties are in favor of the genocide of Palestinians and both actively ensure that it happens. A few decades ago both were purely transphobic and did nit evdn exhibit today’s liberal cooption of the struggle (notice that it has slowed down).

Most importantly, the two-party system prevents popular politics that runs counter to ruling class interests. Their greatest opponents are the left, so the US political system prevents left parties from functioning abd becoming popular. Want to run as a third party? Well the Dems will gladly do a last-minute change to how many signatures you need to gather to get on the ballot. They can meet the number because they will pay people to collect them, but you have to have already prepared a horde of volunteers. Organize a socialist party? They might just plain kill you.

It is not the existence of parties that is the problem, but the stifling of left parties, of those that can challenge the systemic causes of oppression.