Can US Supreme Court decisions be overturned by the Judicial Activism?

Yes, but only the US Supreme Court can overturn its own earlier court decisions.

Judicial activism is a label subjectively applied to legal decisions believed to go beyond the intent of the Constitution or Congressional lawmakers, or to overturn established legal precedent. The term has negative connotations, and is synonymous with the phrase "legislating from the bench."

There is no entity called "the Judicial Activism," nor is there a populist movement by that name; it is simply a concept related to certain types of court decisions.

Supreme Court decisions can only be overturned in one of two ways:
  1. The Supreme Court can overturn its own decisions.
  2. Supreme Court decisions may be overturned by constitutional amendment.

For more information, see Related Questions, below.