An act of the legislature of a government (a statute), which was enacted as a law by the council of a city, county, the legislature of a state or province, or by the national legislature of that country, is unconstitutional when the act's provisions conflict with a constitution or some other law having higher standing than the act in question. When a court decides that the act in question conflicts with the constitution, it finds that law unconstitutional and declares it void in whole or in part. The portion of the law that is declared void is considered to be struck down, as the statute is considered to be struck from the statute books, as a law that is unconstitutional has no effect.
Depending on the type of legal system, a statute may be declared unconstitutional by any court or only by special Constitutional courts who have the authority to rule on the validity of a statute.
In some countries, especially ones not having a formal written constitution, the legislature may create any law for any purpose and there is no provision for a law to be declared unconstitutional.
See also
The content of this page is retrieved from http://en.wikipedia.org/wiki/Unconstitutional under GFDL
