Arguments before the Supreme Court on Tuesday left affirmative action supporters more optimistic than they expected to be that a Michigan ban on racial preference programs might be struck down.

Several justices gave more credence than expected to the argument that by banning affirmative action through an amendment to the state constitution, Michigan had unfairly made it more difficult for minorities to change the policy than non-minorities trying to push analogous kinds of change. The 2006 amendment, known as Proposal 2, forbids using “preferential treatment” based on race, gender or ethnicity in state education, employment or contracting