I am not a knee jerk lefter as some are here but for the sake of discussion I think the left side needs to find examples linking lack of government regulation to market failure or market weaknesses. The best approach other than to draw vague connections between regulation and historical Wall Street instability, would be to argue that unregulated industries tend to exploit other parties. That argument is fairly easy to make. But the rest of it would be to link unregulated industrial exploitation with the markets being ruined or stifled. That argument is much more difficult it seems to me.