First, the revelation that not only was Hsu a fraudster who was enriching himself using a Ponzi scheme, but that his business fraud and campaign donations/bundling were part of a single corrupt enterprise.  In other words, Hsu was engaging in fraud to finance his campaign fundraising operation.  

This isn't really accurate.  Hsu was (allegedly, cough) scamming people out of money, but that money didn't go to political candidates.  Instead, Hsu would pressure the people caught up in his scam (who thought they were making money via Hsu, but it was all a big Ponzi scheme) to give money to specific candidates, implying that if they didn't, Hsu would cut off their gravy train.

I've personally dealt with some of the largest Ponzi schemes in U.S. history.  The people who pull off these scams often get away with it for years, and the whole time, sophisticated business people are fooled into thinking that they're legitimate operators with a real business behind them.

I see no indication that Hillary and the other Democrats who took money from Hsu had any reason to believe he was anything other than a successful businessman with a lot of money and a lot of contacts.

I find it unfortunate that Democrats are trumping up this issue against other Democrats, because at this time there's no reason to believe anyone was guilty of wrongdoing other than Hsu himself, and it's the kind of sexy-sounding Whitewater non-scandal that could become an issue in the general election because most people won't delve down into the details to figure out that the Democrats didn't actually do anything wrong.  I don't like how people bring up this sort of "smoke , but no fire" issue during the primary season as though there are no consequences down the road.