Term limits, ranked choice voting, and laws to fix corruption, to include gerrymandering. Give the people back their power.
Currently, a small minority of races are actually competitive (largely due to gerrymandering), and for a candidate to win they need an incredible amount of money. Very few Americans donate substantial amounts of money, so politicians don't give a damn about them. They care about rich folks, interest groups, and corporations. If you aren't familiar with
RepresentUS, I recommend you watch some of their content and support their cause.
It's a big idea, and one I haven't seen anyone propose... but I think all campaign donations of any kind should be illegal. Each federal campaign that reaches a certain threshold of support to qualify should be given the same set amount of money by the government to spend as they see fit (within ethics/corruption laws). We could, for a pittance, completely eliminate corruption with regards to lobbying, and even the playing field between our 2 terrible parties and independent candidates, allowing the best ideas and candidates to win rather than the best puppets. The problem is that it will never happen, because the corrupt assholes in power would all lose.