You are (more than) a little despairing of the situation, but raise a few good points -

Do we deserve a situation where the two parties both seem lacking in clear, absolute moreal values? Does this simply stem from the fact that the US population is largely centrist, despite the divisive cosmetic differences?

How large a difference can the government make to the everyday lives of ordinary citizen? Can they really drive the changes in society or merely react and manage the apparatus of the state?

Are things so bad they can't be turned around by a good leader? Far from my cup of tea, but Reagan undoubtedly rallied national pride to an unprecedented degree, just a decade or so after Nixon.

If there are enough good, ordinary people left, and I'm sure there are, the US will be just fine in the long run.