It was never really there to begin with. Just the illusion that it was.
IMHO the American Dream is something that can only be brought about by the American people. Not by the government or by capitalists. The government and capitalists have always had their own agenda apart from that of the American worker/consumer/citizen. And their agenda sometimes comes at our detriment. But it doesn't matter to them because they are about money, wealth, territory and control. Or if it does matter to some of them their own interests still are a higher priority to them than our pain.
American capitalism has gone through several stages and it had to change during the New Deal Era or else face the wrath of popular revolution. Now that the threat of popular revolution subsided almost completely in the 1970s as the last rebellion (the rebellions of the 1960s) died out, capitalism can go back to the pre-New Deal days. That's what Ronald Reagan was about, reconstructing 1920's corporate "laissez-faire" for a late industrial society. That's what every politician after him has been about as well. They've just had differing methods of achieving this goal.