> Constitutional changes are required for other countries to trust in the stability of the US in the future.

I don't know about trust but the constitution isn't what enabled this type of behavior, it's the legislature. They've been abdicating their duties to executive controlled bodies (FCC, FDA, FTC, EPA, etc.) and allowing the president to rule through executive action unchallenged. They could have stopped these tariffs on day one. SCOTUS isn't supposed to be reactionary, congress is.

The constitution has all the mechanisms in place to control the president, they just aren't being used by the legislature.

It's a tricky problem that has a number of proposed solutions. I'm not going to act like it's a silver bullet but I think open primaries in federal elections would go a _long_ way towards normalizing (in the scientific meaning) the legislature and allowing people who want to do the job, rather than grandstand, into the offices.

I think the root of the problem is our two party system and the polarization of our culture. Congress and the president often act as a single partisan unit, not a collection of independent thinkers with their own ideas about how the country should be run. That makes it very hard for congress to serve as an effective check on presidential powers.

That's really the achilles heel of a checks and balances system. Should an ideology gain control of all of them then the system doesn't work and it immediately sinks into authoritarianism. The Supreme Court acting on this just unfortunately gives the illusion of things working when it's a game of blitzkrieg. Make an obvious illegal action and get as much done as possible then when you are eventually checked, move on to the next thing. Just keep pushing in different directions until you cover the board.