The presidential campaign is at last truly, officially under way, so this must be family hour. Children and stepchildren of all of the candidates are everywhere, giving interviews to the newspapers and talking heads, and showing up in the glossy magazines, working the crowds, dropping in on the envelope stuffers at campaign headquarters, all with one single purpose. Anything to help Daddy win.

Chris Heinz, stepson of John Kerry, quit his job as a venture capitalist to campaign full time. People magazine calls him one of the hottest bachelors in the country. "It's quite clear you can't believe everything you read," he told Chris Wallace humbly, in a particularly awkward and stiff interview. "I'm sure your viewers are connecting with that fact now."

The young man is handsome and looks at home in expensive casual clothes, but it's cruel and unusual punishment to thrust him to center stage with innocuous tidbits about what a great father his stepfather is. It would be sexist, of course, to say he's only there to thrill impressionable young women who may be registered to vote, but there's the usual gossip that he could become a movie star. He hopes to help soften the sharp edges of his mom's bluntness. That may be the tallest order of all.

Vanessa Kerry serves a different purpose. She tries to humanize her daddy by emphasizing his warm, spontaneous nature. She describes him as "a little boy, jumping up the walls" as he prepares for his acceptance speech. Only a daughter could see the excited little boy in John Kerry.

The Kerry-Edwards clan has been called "The Brady Bunch," likened to the popular 1970s television series about a big and blended family. But the Brady Bunch was never subjected to tacky, tasteless and intrusive questions such as those asked of Cate Edwards and Chris and Andre Heinz on ABC-TV's "Good Morning America." Question: "You've both suffered enormous losses in your family. The loss of your brother, loss of your father. Is that something that has brought the families closer together, or has it come up at all for you?" The question deserved one of Teresa Heinz Kerry's' more colorful replies, but Cate was polite, as candidate's children, like preacher's sons, have to be: "That certainly creates some sort of bond."

The Bush twins, age 22, rarely got any press while they were in college, except for the stories about underage drinking in Texas, but Jenna and Barbara have come out of the fashion closet with a debut in Vogue magazine. They're both beautiful, and their photographs are as soothing as a soy latte for voters under the hair dryer, getting a manicure. The twins look like debutantes, though they insist they had rather be in body-hugging jeans and skimpy tops.

Critics naturally accuse the first daughters of going public to soften the image of their father as "the war president." Probably true, but so what? Jenna Bush could be speaking for all the candidates' children: "I love my dad, and I think I'd regret it if I didn't do this." The twins may be countering that nasty observation of Ann Gerhard, the first lady's unofficial biographer, that Jenna and Barbara were unsympathetic to their parents' burdens and responsibilities, "all noblesse" and no "oblige."

No one ever said it was easy being the son or daughter of a president. Some of the lucky ones found work as presidents of universities, as ambassadors, or joined the military or entered politics. Several have been successful authors; Margaret Truman wrote mystery novels, John Eisenhower wrote military history and Caroline Kennedy wrote scholarly books on the Bill of Rights and the right to privacy. One son of a recent president became president himself, the second son to do it.

In "All the President's Children," Doug Wead catalogs triumphs and tragedies and some trivia in the lives of first children. Alice Lee Roosevelt Longworth, daughter of Teddy Roosevelt, had perhaps the tartest tongue. Calvin Coolidge, she said, looked like he had been weaned on a pickle. The Hoover vacuum cleaner was more exciting than President Hoover. "But, of course, it's electric." She prominently displayed on her sofa a needlepoint pillow stitched with the phrase that characterized her acid wit: "If you haven't anything good to say about anyone, come and sit by me." Said her long-suffering father: "I can either run the country, or attend to Alice, but I cannot possibly do both."

Franklin D. Roosevelt got it right, speaking of his own children, some of whom turned out better than others: "One of the worst things in the world is being the child of a president. It's a terrible life they lead."