The middle class can't be saved unless Wall Street is tamed. Yet most presidential aspirants don't want to talk about taming the Street because Wall Street is one of their largest sources of campaign money. Six years ago ... the financial collapse crippled the middle class and poor, consuming the savings of millions of average Americans and causing 23 million to lose their jobs, 9.3 million to lose their health insurance and some 1 million to lose their homes. A repeat performance is not unlikely. Wall Street's biggest banks are much larger now than they were then. Five of them hold about 45 percent of America's banking assets. In 2000, they held 25 percent. Meanwhile, the Street's lobbyists have gotten Congress to repeal a provision of Dodd-Frank curbing excessive speculation by the big banks. The language was drafted by Citigroup and personally pushed by Jamie Dimon, CEO of JPMorgan Chase. It's nice that presidential aspirants are talking about rebuilding America's middle class. But to be credible, the candidates have to [propose] to limit the size of the biggest Wall Street banks, to resurrect the Glass-Steagall Act (which used to separate investment banking from commercial banking), to define insider trading the way most other countries do (using information any reasonable person would know is unavailable to most investors), and to close the revolving door between the Street and the U.S. Treasury. It also means not depending on the Street to finance their campaigns.