The problem is that the US constitution was written before people realized that the natural consequence of that type of constitution is a two party system. You cannot have a viable third party in the long run because it will necessarily weaken one or the other existing party and that party will then absorb it.

So no you have a situation where the government can have split brain: some parts of the legislative branch can be party A and other parts can be party B and the president isn’t tied to either.

From what I understand when the US “brings democracy” to another country we set up a parliamentary system and that system is widely seen as better. You cannot form an ineffective government by definition, though you can have a non-functioning government that is trying to form a coalition. These types of systems tend to find center because forming a coalition always requires some level of compromise. Our system oscillates between three states: party A does what they want, party B does what they want, and split brain and president does what he wants because Congress has no will to keep him accountable.

What I would like to try is a combination of parliamentary system, approval voting, and possibly major legislation passed by randomly selecting a jury of citizens and showing the the pros and cons of a bill. If you cannot convince 1000 random citizens that we should go to war, maybe it’s not a good idea.

> The problem is that the US constitution was written before people realized that the natural consequence of that type of constitution is a two party system.

The two party system is a consequence of using first past the post voting, which the US constitution doesn't even require. Use score voting instead, which can be done by ordinary legislation without any constitutional amendment, and you don't have a two party system anymore.