Without a constitution, the US would have been at least this bad since the 1970s. Probably worse, and sooner.

The United States has the worst constitution in the Western World.

The US Senate gives a handful of empty states (Idaho, Wyoming) have tremendous political power.

The French Senate is designed to represent all regions, regardless of population size. If there are 50 people living in Champagne, these 50 people will get a Senator. But the French Senate can't stop bills supported by the French Representatives. It can slow them down. It can amend them or improve them. But it can't kill them.

The same way, the Canadian Senate is designed to represent all regions of Canada, from the Atlantic to the Pacific. But the Canadian Senate can not kill bills supported by the Canadian House of Representatives.

The US Senate makes the United States unique. It gives veto power to rural empty areas. It's basically impossible to pass immensely popular legislation like abortion rights. Canada can pass it. The US can't.

Furthermore, the US President is indirectly elected through an electoral college. This means a lot of votes become totally useless. If you vote for a Republican and you live in California, your vote is meaningless. If you live in Alabama and vote for a Democrat, your vote is meaningless. It's a recipe for disenfranchisement.

This also means that all political campaign disproportionately focus on a handful of regions. Most countries that had an electoral college decided to abandon it. The United States almost abandoned the electoral college in the 70s but it failed by two votes.

The US constitution was very progressive centuries ago. But it failed to evolved. Now, it's badly falling behind most democratic countries.

https://www.nytimes.com/2022/09/17/us/american-democracy-threats.html

https://www.theatlantic.com/ideas/archive/2023/09/american-constitution-norway/675199/

https://www.newyorker.com/culture/annals-of-inquiry/the-united-states-unamendable-constitution

Most countries protect the political rights of the minority without preventing the majority from governing. Having regular budget shutdowns is not normal.

Americans fail to see it because they many of them worship their constitution. Keep in mind this is the country where over 100 million people think Donald Trump is an honest man.

To be clear, not all parts of the US Constitutions are wrong. Since 1947, the US prevents the President from exercising more than 2 terms. That's a great thing.