The United States Supreme Court has upheld Michigan's ban on affirmative action.

The justices, in a 6-2 decision issued today, struck down a lower-court ruling that had ruled the ban was unconstitutional.

Groups fighting the ban claim it has resulted in a decline in minority enrollments at colleges like the University of Michigan.

The ban was approved in November 2006, passed by 58 percent of voters. The day after the measure, known as the Michigan Civil Rights Initiative or Proposal 2 was approved, several organizations filed suit to invalidate it.

The measure became law Dec. 22, 2006.

The Supreme Court ruling's lead opinion was written by Justice Anthony Kennedy, who was joined by Chief Justice John Roberts and Justice Samuel Alito. Two concurring opinions were also handed down, one by Justice Antonin Scalia and Justice Clarence Thomas and a second by Justice Stephen Breyer. The three opinions primarily differed on whether to they would limit a particular precedent (Kennedy’s approach), overturn it (Scalia’s preference) or distinguish it (Breyer’s approach).

However, all six justices in the majority agreed that Michigan’s amendment was valid.

“Today’s decision by the U.S. Supreme Court is monumental," Michigan Attorney General Bill Schuette said in a statement. "The ruling is a victory for the Constitution, a victory for Michigan citizens, and a victory for the rule of law."