Final answer:
A public university in Michigan adopting an admissions policy that favors African-Americans would violate state law due to a 2006 referendum banning affirmative action in state education.
Step-by-step explanation:
If a public university in Michigan wished to adopt an admissions policy that favored African-Americans, such a policy would indeed violate Michigan's state constitution. This stems from a referendum passed in November 2006, where a majority of Michigan voters (58%) supported the ban on state-education affirmative action. This effectively overturned the precedent set by Grutter v. Bollinger, where the Supreme Court upheld the use of affirmative action in admissions policies at the University of Michigan Law School to promote diversity.