There are plenty of reasons to change the US Constitution, but I’m wondering specifically about the current dilemma the US seems to be in re the executive seeming to have no desire to listen to the courts. The US Marshals, the law enforcement arm of the judiciary, is ultimately under the control of the executive. What changes would need to be made to the Constitution to ensure that there 1) can’t be a conflict between separate law enforcement agencies in two branches, and 2) the executive branch can never, even theoretically, have the ability to seize control of the government from the other branches?
The first one would be meaningless without an actual change to the election system. There are more than five parties in the US after all, technically speaking, the ones outside the other two simply arent viable because first past the post voting trends towards two dominant parties.