WASHINGTON – The U.S. Supreme Court refused Friday to stop enforcement of the military’s “don’t ask, don’t tell” policy while a lower court hears a challenge to the Pentagon’s ban on gays and lesbians serving openly.

The U.S. Court of Appeals for the 9th Circuit is preparing to hear legal arguments in a case brought by the Log Cabin Republicans. The gay rights group is challenging “don’t ask, don’t tell,” and in September a federal district judge found the policy to be unconstitutional and blocked the Pentagon from enforcing the ban.

The appeals court is not likely to set a hearing on the issue until mid-March, and its ruling could come anytime after that. But the Justice Department persuaded the 9th Circuit to lift the judge’s stay, prompting the Log Cabin Republicans to appeal to the Supreme Court.

The high court’s order Friday came with no explanation and no noted dissent. It provides no clue to how the justices ultimately would rule on the merits of the case, because the only question presented was whether to lift the stay.

Even so, it was notable for one thing: Justice Elena Kagan’s decision to recuse herself from the case. Her decision was not explained, but it likely has to do with her service as President Obama’s solicitor general and her role in decisions about setting the administration’s strategy in response to the suit.

Whenever a justice is recused, that raises the possibility of a 4-4 tie. But in this case, it also robs those who oppose “don’t ask, don’t tell” of a justice likely to be sympathetic. While dean of Harvard Law School, Kagan was an outspoken critic of the policy, Although she told conservative critics during her confirmation hearings — both as solicitor general and for the Supreme Court — that she could separate her personal opinion from her legal analysis.

The potential for a tie also increases the importance of the circuit court’s opinion. A tie means that the lower court’s decision stands but without setting a national precedent.

The American Civil Liberties Union launched a separate legal effort Wednesday against the Pentagon’s policy on gays in the military. The group is suing to change the military’s rules on the amount of separation pay given to service members discharged for being gay.