Some opponents further claim that affirmative action has undesirable side-effects and that it fails to achieve its goals. They argue that it hinders reconciliation, replaces old wrongs with new wrongs, undermines the achievements of minorities, and encourages groups to identify themselves as disadvantaged, even if they are not. It may increase racial tension and benefit the more privileged people within minority groups at the expense of the disenfranchised within better-off groups (such as lower-class whites and Asians).There has recently been a strong push among American states to ban racial or gender preferences in university admissions, in reaction to the controversial and unprecedented decision in Grutter v. Bollinger. In 2006, nearly 60% of Michigan voters decided to ban affirmative action in university admissions. Michigan joined California, Florida, Texas, and Washington in banning the use of race or sex in admissions considerations. Some opponents believe, among other things, that affirmative action devalues the accomplishments of people who belong to a group it's supposed to help, therefore making affirmative action counter-productive. Furthermore, opponents of affirmative action claim that these policies dehumanize individuals and applicants to jobs or school are judged as members of a group without consideration for the individual person.

Answer this question, if possible (if impossible, reply "unanswerable"): Which court case featured an unprecedented and controversial decision?
Grutter v. Bollinger