"But the modern Democratic Party is not likely to embrace left-wing populism the way the GOP has embraced – or, more accurately, been forced to embrace – right-wing populism"
The Dems will try to coopt OWS, but OWS has to take over the Democratic party, not the other way around. They may not be w holly owned subsidiary of Wall Street, like the GOP are, but Wall Street has a majority on the Dem's board, so to speak.
As I wrote elsewhere...
My own view is that OWS has to become the nucleus of a campaign to run candidates ("99 percenters"?) against the most corrupt and complacent Democratic representatives and senators. The Tea Party, in doing this, created so much fear in the GOP that they dragged the whole party to the right. I think OWS can do the same with the Dems (although in the other direction, obviously).
We need to get better Democrats in office, and drag the whole party into a commitment to make sure that the economy works for everyone, and not just for the rich. There would have to be a commitment to modify the rules that allow for obstructionism in congress, so that government works again, and ways have to be found to keep corporate money out of politics.