As argumate@tumblr says, the solution to politics is to have one planet per person.

There are websites that form trees of different arguments/responses/responses-to-responses. I don’t remember any of their names off the top of my head.
I don’t remember the results of such trees being particularly encouraging, though the example I’m remembering on one of those websites was a for/against with a fairly obvious answer, and was a not particularly political topic, more a philosophy debate. The bottom layer was mostly dumb relativist-to-the-point-of-meaninglessness objections.

One idea I’ve heard of, which sounds like it could be useful, is the idea of a “double crux”, a question where both parties agree that if their initial belief about this question was wrong, then so was their initial belief about the bigger question. This potentially allows reducing one question to another, hopefully making it easier to tackle.

But there are multiple things here. One is disagreement about material/positive claims. The other is disagreement about what is to be done. These are, of course, rather connected, but also not entirely the same. It is possible for 2 people to at least be unaware of any relevant positive claims about which they disagree, but still disagree about what to do in light of how things are.

There are mechanisms that should work well for resolving disagreement about material/positive claims, at least provided honest participants, though I think setups can also work which will still work with some level of dishonesty among participants.

But, for disagreements as to what to do given certain positive/material facts, I suspect that these may be more difficult to resolve. That’s not to say that I don’t think they can ever be resolved. People have been convinced by moral argumentation before, are there are valid chains of reasoning about what is right and what is wrong, and people will generally have many moral beliefs in common, and this can provide some shared foundation for the argumentation.

But, unlike with questions of positive/material facts, I’m not convinced that essentially all questions of “what should be done” can be reduced through reasoning to combinations of material/positive facts with principles which both parties agree with.

To be clear, I do believe that there are moral facts.

But possibly some questions of what to do, do not have a single morally obligatory choice, and in such cases, if different people have different preferences, then it is unclear why debate would result in an agreement as to what to do.

(Also, even if there is a moral fact as to which choice would be better in a given topic, it is conceivable that I might be sufficiently wrong about the relevant moral questions that it wouldn’t be feasible to convince me, or at least, not feasible to convince me by the time that the decision has to be made. I mean, hopefully this wouldn’t happen, I don’t want to be in the wrong, but I don’t think it is totally out of the question.)

There is no universal way to aggregate preferences of people. In the end, a system must simply produce a result.
Of course, in some restricted cases, there are ways to combine preferences which I think should be considered optimal. For example, if the thing being decided is a single number, and everyone has a single-peaked preference, in that for a pair of numbers on the same side of their most preferred number, they will always prefer the one closer to their most preferred number, having everyone state their most preferred number and then taking the median (or, if there is an even number of people, a random selection between the middlemost 2) is optimal I think, in that everyone is incentivized to give their honest preference, and no other option will be an improvement from the perspective of more people than think it is a dis-improvement.