The U.S. Supreme Court takes up the issue of affirmative action again Tuesday, but this time the question is not whether race may be considered as a factor in college admissions. Instead, this case tests whether voters can ban affirmative-action programs through a referendum.

In 2003, the high court upheld the University of Michigan Law School's affirmative-action policy. The next day, opponents of affirmative action launched a referendum campaign to bar such programs, and in 2006, voters overwhelmingly approved a ballot initiative amending the state constitution to ban affirmative-action programs in higher education. Michigan's state colleges and universities promptly abandoned any use of race or ethnicity to promote diversity, and minority enrollment plummeted.

In 2012, a federal appeals court ruled that the referendum itself was discriminatory, and the U.S. Supreme Court stepped in to decide the issue.