No, not all politicians are bad.

US democracy is so horrendously flawed, however, that only a few good eggs make it though. They almost serve as an excuse for 'not all representatives are bad' when the vast majority of them are.

I think the true issue is the constituency. Nothing will change until the culture changes. For the culture to change, people need to admit when they're wrong.

I won't hold my breath, personally.

it's not a "shadowy cabal", it's the ruling class, aka the bourgeois class, the owners of the means of production. capitalism's flaws cannot be mitigated because it's because of these flaws that the system itself can exist (exploitation of workers in different degrees, exploitation of the 3rd world, revenue concentration in the hands of a few, wars and misery etc etc)

the system won't work well for the people because that's the whole point of the system's existence since its inception. it works for a particular class and only that class. the problem isn't Democrats vs Republicans, it's capitalism vs the working class. you don't have to vote, you have to join worker's unions, a socialist/communist party, be an activist, and when duty calls, participate in the revolution that is to come. the only real material change comes when the working class takes power and actually makes way for changes in the socioeconomic status of the country/world. I suggest reading some of Marx's work

With that said, I do agree that in some aspects the Democrats are "better", such as LGBT rights and such, but that could be 10 times better if the people were actually in charge instead of a few rich lobbyists.