WASHINGTON -

Michigan's ban on affirmative action and racial preferences came under attack before the U.S. Supreme Court Tuesday.

The Supreme Court seems prepared to uphold the voter-approved ban on taking account of race in college admissions.

The 7-year-old ban was overturned in the Court of Appeals two years ago for violating the U.S. Constitution.

The Supreme Court is not being asked to rule on racial preferences or the practice of giving minorities an enhanced scores on their admissions applications; that issues has been decided already.

But rather, the way Michigan's ban was achieved is under attack.

The timeline:

2006: 58 percent of Michigan voters approved banning racial preferences in a statewide ballot initiative and locked it into the constitution.

2011: The U.S. Court of Appeals ruled referendums and constitutional amendments make it too difficult for minorities to change admissions policies

2013: Now the high court must decide if the referendum was a violation of the U.S. Constitution.

The court heard arguments Tuesday over the 2006 change to the state constitution to prohibit the University of Michigan and other state schools from any consideration of race when they decide whom to admit.

The justices' focus was more on whether they could craft a narrow ruling to uphold Michigan Proposal 2 or would have to overrule earlier cases that protect minorities' rights to participate in the political process.

Affirmative action supporters say the amendment itself is a form of discrimination because of the burden they face to repeal the constitutional provision.

Several busloads from Michigan joined anti-Proposal 2 demonstrators who protested during the court's oral arguments.

The protestors fear if the Michigan's ban is upheld it will lead to affirmative action bans across the country.

"This is an attempt to end racial diversity at these schools and if upheld will succeed," said one protestor.

Justice Rosenbaum told the other justices the path to change admissions policies is unfair to minorities. that if athletes, musicians or other students want special consideration, they go to the university regents.

Proposal 2 defenders say they are confident the Supreme Court will uphold Michigan's law and see today's action as an attack against citizen democracy.