"Transgender discrimination is, by its very nature, sex discrimination," Justice Laurie McKinnon wrote in the court's decision. "Government issued identification documents are necessary to access public life. When they do not accurately reflect a person's sexual identity, the transgender Montanan is prevented, based on their sex, from obtaining the same attributes of public life that a cisgender Montanan may obtain. Hence, the inability of transgender Montanans to receive government-issued identification documents accurately reflecting their gender identity is fundamentally about the nature of sex and suspect class discrimination."