1. Eliminate / work around the electoral college system, which makes it so that people in the most diverse, educated, and economically-productive parts of the country have dramatically less voting power than a small minority of people who live in more homogeneous, less educated, and less economically-productive areas. This would significantly change the messaging needed to win.
2. Eliminate first-pass-the-post voting, which encourage candidates with extreme views, eliminate anything other than (largely false) political binaries, make it possible to win elections while receiving a minority of the votes, and make it so that the only viable strategy is to vote for the lesser evil rather than somebody you actually want.
3. Get the money out of politics. Make untraceably-funded super-PACs illegal.
4. Gerrymandering should be super fucking illegal.
Other places do this. They're more democratic than the US, and while they still frequently elect stupid politicians, none of those are as bottom-of-the-barrel as what the US is able to scrape together.