Judicial activism is desirable and important because it allows judges to re-evaluate and reinterpret old laws and precedents in terms of modern society. However, it has become one of the most polarizing and controversial topics in the U.S. government because of the vast impact it has on society and policy.
There are two major sources of reference that judges at any court level, but especially the Supreme Court, use to make a decision in a case. First and foremost, judges look at the Constitution of the United States. This document is the ultimate source for determining what rights citizens do or do not have, and Supreme Court judges are faced with the task of interpreting the statutes it puts into place. The second consideration judge make is based on precedent. Precedent is any ruling established by a previous court that clarifies a question of rights in a constitutional case.
The problem the courts face is that the Constitution was established hundreds of years ago in a different society than subsequent ones. The same can be said for the rule of precedent. Judicial activism is good because judges can make an informed decision on how to apply an outdated law or precedent to a current society and culture.