is that not a contradiction? how can a person filing a lawsuit in a class action case have a “unique” and vested” interest?
A typical class action will allege that the defendant cheated a large group of people (e.g., all of the investors in Madoff's hedge fund). The named palintiff has standing (Madoff stole his money) and so do all of the class members. The class-action device merely permits a large number of people to aggregate their claims and sue together (saving the court and the parties the time and trouble of bringing hundreds of separate lawsuits), but each class member must have standing.