A Supreme Court ruling against gay marriage would set up a new round of state-by-state fights. Some of those battles would occur in court, as judges sort out the effects of earlier rulings legalizing marriage.
Other fights would take place at the ballot box. Marriage advocates could try to put the issue before voters in Ohio and Michigan, two presidential swing states where gay marriage is currently illegal.
Supporters might also look to Arizona and Colorado, states that now have gay marriage because of court rulings. A Supreme Court decision potentially would nullify those rulings, forcing supporters to turn to ballot initiatives.
The fracas would leave Republican candidates in a bind, forcing them to try to placate the social conservatives who are key to winning the party’s presidential nomination without alienating middle-of-the-road voters who support gay marriage and who are key to winning the general election.