I think most of them are caused by the two-party political system in the U.S., where parties do make everything seem like an "us vs them".
For every proposal one party has, the other party tends to have the opposite proposal. Except when it's about giving the military bigger budgets, the NSA more surveillance powers, and expanding U.S. military operations in more countries. On those issues both parties are BFFs.
The two party system has got to go, if for no other reason than that it leaves very little room for the competition of ideas.
I think a preferential voting system would be the first step to dismantling the two party regime.
It would make it "safe" to vote for an independent candidate without people feeling like their vote was being thrown away. In time, that would lead to more specialized parties running.
I think for the most part it's the two party system that causes us to see the separate solutions as opposite rather than the other way around. It's hard to think of the trump tax plan as the exact opposite of a democratic solution because it has some measures democrats originally liked and some they originally proposed (although the core thrust of it is quite republican). We also still have it be the case that the majority of motions in house or senate get bi-partisan up-down votes.
Or perhaps most convincingly, as a former Canadian living in the US, I see the democrats as far to the right of the Canadian Conservative party (Canada's right wing party) on healthcare and the Republicans as some radical far-right. It's hard to think of the two solutions as opposites in any meaningful way because from a global perspective it seems like the Republicans want to do 3/100 on healthcare and most of the democrats try and stretch that to maybe 10/100.
This is often overstated. While there's certainly a lot of aspects of American government where both sides are to the right of Canada (or whatever social democracy you want to insert), it's by no means completely universal.
Take immigration - Canada has merit-based immigration with language requirements, and not a lot of tolerance for illegal immigration, which is considered firmly a right wing position in the states.
For every proposal one party has, the other party tends to have the opposite proposal. Except when it's about giving the military bigger budgets, the NSA more surveillance powers, and expanding U.S. military operations in more countries. On those issues both parties are BFFs.
The two party system has got to go, if for no other reason than that it leaves very little room for the competition of ideas.