The U.S. Supreme Court on Wednesday concluded its historic two-day scrutiny of the thorny issue of same-sex marriage, displaying wariness about ruling on the subject even as it appeared possible that the justices will strike down the federal Defense of Marriage Act.

With hundreds of partisans on both sides parading and debating in front of the court on Tuesday and Wednesday, the justices inside probed all aspects of the issue, from the philosophical and political to the procedural.