What standard does the supreme court use to determine whether classification by sexual orientation violates the equal protection clause?

The standard used by the Supreme Court to determine weather or not a classification by sexual orientation violates the equal protection act is minimum rationality standard. This standard, often referred to as Rational Basis Standard of Review, stipulates that the law must have a rational connection to a legitimate goal that the government has. It is higher if the law could be affecting fundamental rights like due process or equal protections.