Though states with marriage-protection amendments on their ballots have enjoyed a 100-percent success rate in passing them, there's a possibility that could change tonight.
In Arizona, with 86 percent of precincts reporting, Prop. 107 -- the amendment defining marriage as the union of one man and one woman -- was trailing at the polls, 48-52 percent.
The reason? Early voting in Maricopa County. Cathi Herrod, president of the Center for Arizona Policy, said there were 300,000 early-voting ballots that had yet to be counted.
"The trend tonight is not good, but until we know exactly what the situation is with those ballots in Maricopa County," she said, "we're not going to concede."