re: Bernie funneled $200k of campaign cash to his wife's non-profit institute...

Most people think their Rep is good regardless if the person is an awful representative and the issues are related to everybody else's reps. It is hard to beat an incumbent. They get the political contributions and then they just run on for or five issues they know get them reelected. They don't want to talk about important issues outside what their political staff has told them to talk about. Term limits would help with this issue.

Our system has lasted about 250 years. The main reason democracy is failing in the US is that unelected bureaucrats (4th branch of Govt that is not mentioned in the Constitution) have too much power and are not accountable to anybody. That has been caused by both of the two major parties. IMO, the best way to end that is bust up the two party system.

The national debt will cause a major collapse in the U.S. in the not too distant future. I can't say exactly what the consequences of that will be. It will not be pretty.

In short it is not just one thing in terms of your question "is democracy failing".