I would like to propose a simple definition of judicial activism in the context of our constitutional arrangements, including checks and balances. Judicial activism is the adjudication of cases in a fashion which produces a result inconsistent with the language and intent of the constitution. The “action” in the “activism” is essentially altering the constitution, usually for the purpose of achieving a desire outcome. Striking down a measure which radically expands the power of the government is the virtual opposite of judicial activism or, judicial restraint.
Obama, the brilliant constitutional scholar (major sarc)knows this but uses the word “activism” to confuse the public into thinking that any significant action by the court is “activism”. As dramatic as striking down 0-care would be, it is actually circumscribing government power within the language of the constitution.