The problem with the U.S. system is twofold: first, an unusually high amount of cooperation is required to pass any law (majority of the House, 60% of the Senate, and the presidency). Second, the first-past-the-post electoral system naturally leads to a two-party duopoly and polarization that makes cooperation very difficult. No other democracy in the world has both of these flaws although some have one of them (e.g. the UK).
The best systems in practice seem to be proportional-representation parliamentary ones. They generally result in coalitions of multiple generally centrist parties so things don’t change too abruptly, but passing new laws is at least possible. Of course some parties refuse to cooperate with each other: in Germany for example no mainstream party will work with the right-wing AFD, and right-leaning mainstream parties additionally refuse to work with the left-wing Die Linke (legal successor to the East German ruling party although substantially more moderate nowadays). However this doesn’t stop the big mainstream parties from working together to an extent that would be unimaginable in the U.S.
It’s indeed probably impossible to fix in the U.S. because it’s so hard to amend the constitution in such a radical way.
> The best systems in practice seem to be proportional-representation parliamentary ones. They generally result in coalitions of multiple generally centrist parties so things don’t change too abruptly, but passing new laws is at least possible.
When there are two major parties each representing say ~45% of the population, proportional-representation gives the left over swing voters equal power does it not? So perhaps ~6% of swing voters can have as much influence as ~45% of voters? Does this not happen in practice? Consider Israeli proportional-representation system for example. The Israeli % numbers are different but I have the impression they struggle with this problem due to proportional-representation.
It's less likely for two stable parties to make up 90% of the electorate in such a system, because splitting parties is much easier. If the US had proportional representation, there's no way Nikki Haley and Marjorie Taylor Greene would be in the same party, nor Bernie Sanders and Kamala Harris. But this split will never happen in the current system because leaving one of the two major parties would be electoral suicide.
There are ten factions represented in the Knesset (Israeli parliament) and the biggest one (Likud, Netanyahu's party) got 23% of the vote in the last election.
It's true that fringe parties can have outsized influence in a proportional system, but the US system suffers from the opposite problem: fringe elements can take over one of the major parties, which seems to be well on its way to happening with the Republicans now.
The best systems in practice seem to be proportional-representation parliamentary ones. They generally result in coalitions of multiple generally centrist parties so things don’t change too abruptly, but passing new laws is at least possible. Of course some parties refuse to cooperate with each other: in Germany for example no mainstream party will work with the right-wing AFD, and right-leaning mainstream parties additionally refuse to work with the left-wing Die Linke (legal successor to the East German ruling party although substantially more moderate nowadays). However this doesn’t stop the big mainstream parties from working together to an extent that would be unimaginable in the U.S.
It’s indeed probably impossible to fix in the U.S. because it’s so hard to amend the constitution in such a radical way.