Why is American pluralism said to have a “dual nature”?

What will be an ideal response?

Pluralism has two sides. On the one hand is the Washington System: a wide variety of organized interests focused on narrow interests and profit motives. But on the other hand, membership organizations with wide membership are also heavily involved in American politics. These reflect the fact that interest groups can be portrayed both as “special interests” and also as civil society/democratic organization that will naturally arise in a free society.