WASHINGTON -- The Supreme Court agreed Friday to take up the controversial issue of transgender rights, instantly transforming what had loomed as a holding-pattern term with only eight justices into one featuring another major social policy issue.

The justices will consider a Virginia school district's challenge to Obama administration regulations requiring that schools allow transgender students to use restrooms matching their chosen gender, rather than birth gender.

A federal appeals court ruled in April for high school student Gavin Grimm in one of several lawsuits challenging the Department of Education rule. The justices could have sidestepped the issue pending action by other appellate courts but decided to wade in now. The case is likely to be heard by April and decided by late June.

Grimm, a 17-year-old high school senior in Gloucester County, Virginia, identified as a boy several years ago and eventually sought to use the boys' bathroom in school. He is represented by the American Civil Liberties Union, whose legal director, Steven Shapiro, said, “We want to get it resolved for his benefit as fast as we can.”

But 23 states, including North Carolina and Texas, have challenged the administration's right to interpret its own regulations without legislative action or judicial review. And several conservative justices have argued in the past that agencies have no such power.

The justices in August blocked the lower court's ruling from taking effect while they considered hearing the case. By agreeing to do so now, they likely are hoping that a ninth justice will be confirmed by the time the case is heard. But with Senate Republicans blocking President Obama's nomination of federal appeals court Judge Merrick Garland, that is far from guaranteed.

If the court goes forward with only eight justices, it could produce a tie vote that leaves the lower court's decision intact. That would be a victory for Grimm and the ACLU, but without national precedent.

The battle over so-called bathroom bills has played out in many states as conservative lawmakers seek to force students to use facilities that correspond to their gender at birth, and transgender students fight for the right to follow their gender identity.

Grimm's case is based on the Constitution’s guarantee of equal protection as well as Title IX, a federal law that bars sex discrimination in education. The Education Department invoked that law when issuing its guidelines in May, threatening federal enforcement -- including the loss of federal education funds.

The Virginia lawsuit had been decided by two federal courts by the time the administration weighed in. Since then, about two dozen states have filed suit against the guidelines.

In August, a federal judge in Texas sided with school districts opposed to the directive, preventing the Education Department from implementing its guidance nationwide. Judge Reed O'Connor said federal agencies exceeded their authority under the 1972 law banning sex discrimination in schools. That case is now pending before another federal appeals court.

Without Supreme Court intervention, school districts in the 4th Circuit -- which includes Virginia, Maryland, North Carolina, South Carolina and West Virginia -- would be bound by the appeals court ruling in Grimm's favor, while all other school districts would be bound by the Texas judge's decision blocking the administration policy.

The Gloucester County School Board's appeal has garnered broad support from conservatives, including 20 states, 114 members of Congress, and former Education Secretary William Bennett, who argued that under Title IX the term "sex" refers to an "immutable physiological characteristic, not an individual's self-reported 'internal sense of gender.'"