Judicial nullification

Judicial nullification is a right of a judge to nullify (make invalid) a law if they feel it is too harsh in a certain situation where it is being applied. During the Constitutional Convention many, including George Mason, Elbridge Gerry and James Wilson felt the courts could decide if a law was unconstitutional, and if so, refuse to enforce it. Other founding fathers including John Francis Mercer, Gouverneur Morris and John Dickinson argued against allowing judges to have that power. The issue was left unanswered. However, when deciding that a new law needed the approval of the president, all attempts to have the judiciary approve new laws were soundly defeated. Judicial Nullification is sometimes used to mean jury nullification. More often it means nullifying a law, legal code or statute by a member of the judiciary.
In 1832 South Carolina said a new tariff law was unconstitutional, thus not really a law. Vice President John C. Calhoun agreed, but President Andrew Jackson disagreed. Jackson threatened to send troops. The two sides negotiated. Congress changed the tariff, and South Carolina decided the new law was not against the Constitution.
In 2011 the Supreme Court made a ruling that, in essence, says lower court judges can ignore the law. There were three petitions before the Court asking if federal courts need to be stopped from ignoring laws, rules and facts. The Supreme Court refused to grant "certiorari" (a writ seeking judicial review of a matter). In other words, the Court refused to consider the three petitions.