By Ben Smith

October 24, 2004 | 8:00 p.m

Cate Edwards got halfway through her sentence when the crowd at a gay-rights fund-raiser cut her off.

"While my father and I don’t share the exact same view on marriage …. " John Edwards’ 22-year-old daughter had begun, and the room at the Sheraton New York erupted in applause. Everyone knew what she meant. "We assumed she supported gay marriage," said Alan Van Capelle, the executive director of the Empire State Pride Agenda, which hosted the Oct. 14 dinner. Ms. Edwards isn’t the only dissenter on this issue: John Kerry’s younger daughter, Vanessa, made her own view plain at the Democratic National Convention in Boston. "I personally believe in gay marriage," she said. Mary Cheney, as you may have heard, is actually a lesbian; she also served as a board member of a gay Republican group, the Republican Unity Coalition, whose founding statement calls for "full civil equality for all," and which reacted with disgust to the Federal Marriage Amendment. Only the Bush twins have stayed off the record on gay marriage, but they did cheerfully accept an invitation to their make-up artist’s celebration of his gay wedding. This is the generation gap writ large. Even the candidates’ kids, in the ultra-disciplined world of Presidential politics, can’t seem to stay in line. This quiet breach between fathers and daughters is a sign of the coming acceptance of gay marriage, and a sign that the 20 Senators who sponsored the Federal Marriage Amendment, and the President who backed it, will likely live to be embarrassed by their positions. The numbers speak for themselves: A CBS News/ New York Times poll last year found that Americans under 30 favored gay marriage by 61 percent to 35 percent. People 65 and older opposed it by a 73 percent to 18 percent margin. In 20 years, that first group will be running the country; the second will be passing on. If conservatives see an urgency in rushing gay-marriage bans through state legislatures, it may be because demographics are closing their window of popular support. Those shifting sands may also explain why the Democratic daughters’ positions aren’t just more liberal than their fathers; they’re clearer. Mr. Kerry and Mr. Edwards both stick to the gnomic refrain, "I believe that marriage is between a man and a woman." At its minimum, that’s just a dictionary definition. The rough outline of their position is that states should do what they want and won’t be forced to honor each other’s decisions. What it means for the federal benefits of marriage—from the tax code to immigration law—is less clear. Ms. Kerry’s stance, by contrast, makes those answers obvious. Ms. Edwards, for her part, tried to play down the gap between her father’s delicate position and her own implied views. "We all agree on the issue of fairness, the issue of equality," she said. The goal, she said, is "real equality—meaning that two people in a committed, long-term relationship, regardless of who they love, should be able to have equal rights under the law." There’s something painful, and a little unseemly, in watching this argument go on inside political families. It’s not something that’s going to be argued out; it has as much to do with comfort levels and intuitions than with rational argument. Vice President Dick Cheney is the one who has been drawn most publicly into this generational breach. On one hand, he’s made it clear that he quietly differs with President Bush’s attempt to amend the Constitution to prevent his openly lesbian daughter from marrying her partner. On the other, he’s openly "angry" that Mr. Kerry would mention that his daughter is a lesbian. Mr. Kerry’s remark did come across as nasty, but its real nastiness came in revealing Mr. Cheney’s impossible, incoherent position between his daughter and the President. Mr. Van Capelle, of the Pride Agenda, said he hopes the children will bring their fathers around. "Everybody else in the White House lives in a bubble," he said. "The children are the only people who are in contact with the real world, and they’re whispering in their fathers’ ears because they have the best feel for what’s happening in America." One tantalizing moment in the generational shift arrived unexpectedly in the midst of the gay-marriage fight this summer, when Irwin Gomez invited Jenna and Barbara Bush to a Maryland party to celebrate his San Francisco wedding to James Packard. Mr. Gomez is a makeup artist at a Chevy Chase salon; he does, he said, the Presidential daughters’ eyebrows. "They said, ‘We’ll try to make it,’" he said. "They knew I was married to a man, and they were cool." News of the invitation, however, hit the press, and the Bushes did not show up at the celebration last month. "I had a feeling that the father didn’t want them to come," Mr. Gomez said.