In other regions, hearings have not yet been scheduled but are considered very likely this year in the Ninth Circuit, in San Francisco, regarding a 2012 decision that upheld Nevada’s restrictive law. They also could occur this year in the Fifth Circuit, in New Orleans, for the Texas case, and in the Sixth Circuit, in Cincinnati, for cases from Michigan, Ohio and Kentucky.

Given the consistency of recent court decisions and the signals given by the Supreme Court in its ruling in June, many experts predict that some if not most of these circuit panels will uphold marriage rights for gay and lesbian couples. That could upend law in many conservative states.

The 10th Circuit, for example, includes Wyoming and Kansas, while the Fourth Circuit includes North Carolina, South Carolina and West Virginia.

Given the potential wider impact of circuit decisions, pressure will be intense on the Supreme Court to address the issue head on rather than skirting it as it did last year, when it allowed a decision overruling California’s ban on same-sex marriage to stand on grounds that did not apply to other states in the Ninth Circuit.

The Supreme Court will be all but forced to decide if, as appears possible, different circuits reach clashing conclusions. The one most likely to decide against same-sex marriage, many experts say, is the Fifth Circuit, which will decide the Texas appeal. That circuit includes Mississippi and Louisiana, and the court is viewed as largely made up of conservative judges.

The Supreme Court’s term runs from October to June. With the high likelihood that at least one circuit will decide against state limits by summer or fall, observers say, the Supreme Court should have ample time to hear a case for a decision by June 2015, though unexpected delays could push it to 2016 at the latest.

Even as drama unfolds at higher judicial levels, more than 50 challenges to marriage limits are working their way through lower federal courts and state courts. In the next three months, federal district courts will hear challenges in Idaho, Oregon and Pennsylvania, said Gary Buseck, legal director of Gay and Lesbian Advocates and Defenders.