I would say the current party dynamics are a big problem, both the symptom and cause of other problems.

One party fights for total control, with near total resistance to the other party, playing a negative sum game in order to maintain power despite demographic disadvantages.

The other party has a wider spectrum of views, and is more open to bipartisanship. But it has difficulty strategically unifying when it would make the most difference. So it often negotiates from weakness despite having demographic advantages.

As far as I can tell, this dynamic is getting even worse and infecting most people and many institutions that would be much better not being politicized.