NC Votes on Constitutional Ban on Gay Marriage The national debate over gay marriage turns its attention South on Tuesday, as North Carolina could be on the verge of becoming the next state to pass a constitutional amendment defining marriage as solely between a man and a woman. In the final days before the vote, members of President Barack Obama's cabinet expressed support for gay marriage and former President Bill Clinton recorded phone messages urging voters to oppose the amendment. Supporters of the amendment responded with marches, television ads and speeches, including one by Jay Bakker, son of late televangelists Jim and Tammy Faye Bakker. The Rev. Billy Graham was featured in full-page newspaper ads backing the amendment. Experts expect the measure to pass, despite the state's long history of moderate politics. North Carolina law already bans gay marriage, but an amendment would effectively slam the door shut on same-sex marriages. The fate of the amendment hinges on who shows up to vote. More than 500,000 voters had cast their ballot before Tuesday, more than the 2008 primary when Obama and Hillary Clinton were fighting for the Democratic presidential nomination. Both sides said that bodes well for them. Obama, who supports most gay rights, has stopped short of backing gay marriage. Without clarification, he's said for the past year and a half that his personal views on the matter are "evolving." His election-year vagueness on gay marriage is coming under fresh scrutiny. Education Secretary Arne Duncan broke ranks with the White House on Monday, stating his unequivocal support for same-sex marriage one day after Vice President Joe Biden said he is "absolutely comfortable" with same-sex married couples getting the same rights at heterosexual married couples. Older voters, who tend to be more reliable voters, are expected to back the amendment. State House Speaker Thom Tillis, a Republican from a Charlotte suburb, said even if the amendment is passed, it will be reversed as today's young adults age. "It's a generational issue," Tillis told a student group at North Carolina State University in March about the amendment he supports. The amendment was placed on the ballot after Republicans took over control of the state legislature after the 2010 elections, a role the GOP hadn't enjoyed for 140 years. The amendment also goes beyond state law by voiding other types of domestic unions from carrying legal status, which opponents warn could disrupt protection orders for unmarried couples. I understand that we already have a law on the books invalidating gay marriage. I feel like it's really important to stand up and be heard against any further discrimination," elementary school teacher Amelia Rogers of Raleigh said before casting her ballot last weekend. That's the No. 1 reason why I'm coming out to vote today and it's against any further discrimination. Those who oppose changing the traditional definition of marriage to include gays and lesbians said the amendment is the only chance average people have to weigh in.