Associate Supreme Court Justice Elena Kagan said it’s important the public understands the courts as “legitimate” and that a lack of public trust should address that concept rather than popularity of court decisions.“Sometimes the court’s opinions are not popular, and sometimes the court shouldn’t be doing things that are popular,” she said Wednesday at Northwestern Pritzker School of Law.She said by legitimacy, she was referring to an “underlying sense that the court is doing its job.” “I would say a court is legitimate …