I find the term "judicial activism" to largely be meaningless. There is often no discernible line between "making law" and "applying the law." But I do think judges engage in judicial activism when they shed their robes on take on the role of advocates. It certainly happens that judges will give guidance or hints to advocates, especially pro se litigants, to help move cases along. But there is no reason for judges to raise issues that are not presented by the parties. The "party presentation" principle ensures that judges do not transgress this line.
Yet, judges seem to forget their role. The Fourth Circuit, in particular, has been summarily reversed twice in one term for violating the party presentation principle. In November, the Supreme Court SumRev'd the Fourth Circuit in Clark v. Sweeney You might think the judges in Richmond would take a hint, but no such luck. Yesterday, the Supreme Court summarily reversed the en banc Fourth Circuit in Margolin v. National Association of Immigration Judges. I wrote about this case back in December.
The Court explained that the party presentation principle prevents judges from becoming inquisitors:
