SAN JOSE, Calif. — From the racial makeup of University of California classrooms to the number of minority contractors working on BART projects, California’s 17-year ban on affirmative action programs has indelibly marked the nation’s largest state.

But now the debate over whether that experiment has caused more harm than good will take a back seat to a larger national question: Are laws such as California’s affirmative-action ban, Proposition 209, unconstitutional, and should be overturned?

On Tuesday, the U.S. Supreme Court will hear arguments in a challenge to Michigan’s Proposal 2, a 2006 voter-approved law that mirrored Proposition 209 by barring the use of racial and gender preferences in public programs such as university admissions.

Although the justices specifically are reviewing a federal appeals court ruling invalidating Michigan’s law, California’s 1996 version is front and center in the case. The 9th U.S. Circuit Court of Appeals in 1997 upheld Proposition 209, as has the California Supreme Court.

All sides in the explosive issue have made it clear that the outcome will decide the fate of Proposition 209. If the high court lets Michigan’s law die, it would likely doom California’s as well. However, most legal experts predict the conservative Supreme Court is likely to leave the laws intact.

“This obviously is it,” said George Washington, a civil rights lawyer who has worked to overturn the California and Michigan laws. “I think we have an uphill battle, but I definitely think we can win.”

Ward Connerly, a former UC regent and architect of Proposal 2 and Proposition 209, agrees that the Supreme Court could provide the final word. He says he “shudders to think” what would happen if affirmative action is returned to California. “You’re going to see a reinstitution of racial preferences the likes of which we’ve never seen,” he said.

For Proposition 209’s critics, that would not be bad news. California, joined by five other states and the District of Columbia, has urged the Supreme Court to declare Michigan’s law unconstitutional.