The American Sports Council (formerly the College Sports Council) has sued the Department of Education in federal court, arguing that the enforcement of Title IX's three-prong test against high schools violations the U.S. Constitution's Equal Protection Clause. College Sports Council and other anti-Title IX organizations have challenged Title IX's constitutionality in the past, though never successfully. I predict that the court deciding this case will apply the same interpretation as those earlier decisions holding it was not unconstitutional for Title IX to offer a proportionality test as one of three options for compliance . Though those earlier decisions were all in the context of disputes about college sports, there is nothing about applying those arguments to the high school context that warrants a different result.
For more coverage, see this thorough post on Education Week's Schooled in Sports blog.