WASHINGTON  House Republicans quietly moved Friday to uphold the Defense of Marriage Act, the 1996 law that bans federal recognition of same-sex marriages, saying they would step in to argue for the measure’s constitutionality after the Obama administration’s decision to stop defending it.

Republican leaders had the option of inserting themselves in the case by introducing a resolution on the House floor and allowing members to speak out on the issue. Instead they released a statement of their intent on a Friday afternoon when the House was out of session.

By choosing that route, Republican leaders illuminated a central problem they face in the 112th Congress: how to reflect the priorities of traditional social conservatives when much of the party’s energy is focused on the federal budget and the national debt, the animating passions of the freshman class of lawmakers.

Gov. Mitch Daniels of Indiana set off a debate within the party last month when he warned fellow Republicans not to get bogged down in the cultural wars of yore and to “agree to get along for a little while” on social issues.