I have an ongoing debate (argument? fight?) with my father about this. He recalls a time when it felt as if there were 'good guys' in politics, and can't understand why it is that I'm so hard on the democrats (this has begun to shift in recent months as Chucklefuck and Aipac Shakur have consistently disappointed him). Besides the obvious issue of republicans being a lost cause, it's policies like too big to fail and dodd-frank and nafta that created the conditions for our current mess, all the while expanding and allowing basic, obvious bad policy to persist (presidential pardons, executive order powers, life terms in the supreme court).
A five year old can see the problems with a lot of this stuff, which once upon a time you'd defend with vague notions of a self-policing culture or the ghost of ethics in governance. Those kinds of non-safeguards can work fine in a stable system, but they inherently rely on foreknowledge of future conditions not changing in unpredictable ways.
The self-reinforcing recursive loop underlying all this is that the systems of governance can only be changed by the governors. I'm becoming increasingly convinced that democracy will fail so long as it's representative - the incentives to fix the system itself are simply not there because any inefficiency is exploitable for personal gain (so why fix it?) The doomsday proposition that comes out of that though is that the system cannot be changed - only replaced once it decisively breaks. Maybe that's what all this is. I would hate to find another bottom but I fear there's more to go before we get there.