My treatment would be to first try to address the root cause of polarization, which is in large part social media. Somehow eliminate the foreign troll farms that have been caught running far-right and far-left Facebook groups for example. Mandatory proof of humanness.
Then try less extreme civic measures like more Federalism and a weakening of the executive.
I'm not American, but it doesn't sound to me like this is less radical of a solution. For a country that espouses the principle of free speech so passionately - in my experience, from both sides of the political divide - for the USA to require a form of 'proof of credibility' before allowing a citizen to participate in social and political debate would be for it to lose perhaps the most important part of its identity. Would that situation preserve 'America' more than a collection of not-so-united states which would probably retain bilateral trade and travel agreements, as well as the now-immutable, deep-rooted cultural ties?
My treatment would be to first try to address the root cause of polarization, which is in large part social media. Somehow eliminate the foreign troll farms that have been caught running far-right and far-left Facebook groups for example. Mandatory proof of humanness.
Then try less extreme civic measures like more Federalism and a weakening of the executive.