The last time Utah got into a dustup with the United States government over legal questions regarding marriage, federal troops were involved. This time phalanxes of lawyers are doing the fighting, with the state's 2004 constitutional ban on same-sex marriage at issue. But history holds an astonishing twist that could present the appeals courts with a dilemma.

The latest case involves the Dec. 20 decision of a U.S. district judge overturning Utah's ban on same-sex marriage. More than 2,000 Utahans promptly plighted their troth...