By Wednesday, the Bush girls had toned down their sister act.

Wearing tight jeans and their signature trendy tops, they were back at the Madison Square Garden podium where the night before they had giggled their way through a sometimes risque introduction for their father.

Now they were going to introduce Andy Card, the president's chief of staff, before a few hundred young Republicans attending a youth session. Jenna started out safely with a baseball anecdote from the days when her father owned the Texas Rangers.

"One Labor Day, when the temperature was 108 degrees, I was the only family member crazy enough to accompany my dad to the stadium," said Jenna. "After hours of complaining about the heat, I desperately tried to embarrass him out. I covered myself from head to toe in wet paper towels, hoping he would finally take me home. But we stayed to the end. Dad always supports his team to the very last pitch," and here she paused.

The audience applauded politely. The twins were back on message.

Recent college graduates who are deferring the world of work until after Nov. 2, the 22-year-old Bush girls have plunged this week into the convention swirl. Protected from politicking in their father's previous races, both have said they wanted to help campaign this time around. Their Democratic counterparts, Vanessa and Alexandra Kerry, have been on the stump for their father for months, speaking out on the issues and giving media interviews. The twins are younger and, clearly, still emerging as campaigners.

But the Bush family is a political dynasty, and in a tight race, all hands are needed on deck. The former president and first lady have been giving interviews. President Bush's sister, Doro, has had a frenzied speaking schedule here this week. At the youth convention Wednesday, the twins were introduced by their cousin George P. Bush and his wife of three weeks, Mandi.

Until this summer, Jenna and Barbara, with their parents' support, had resisted involvement in their father's work. Their parents firmly protected their privacy, and White House aides refused to comment every time the twins wound up in tabloid reports for their clubbing or on the police blotter for their underage drinking. "They just want to do like every other teenager does," Laura Bush said when asked about her daughters' behavior.

Every other teenager or twenty-something, of course, does not race around Manhattan in a motorcade, protected by frightening men with heavy armament. Or have a platoon of aides to carefully roll out a red carpet and smooth out the wrinkles to prevent the errant twist of an ankle cradled atop a stiletto heel.

That's how the week started Sunday night, when a pair of black Suburbans screeched to a halt about 10:30 in front of the Roseland Ballroom in Midtown. "All press, get into the pen!" the security men barked. The television cameras clicked on. The still photographers jostled. The twins needed two vehicles, an aide explained, because they had so many friends in their posse. A bus earlier had disgorged the B-list friends. The A-list friends got to ride with the political princesses.

The girls walked the runway alone, paused, smiled and obliged the shouts from the paparazzi to put their cheeks together like Mary-Kate and Ashley, only not anorexic. They said nothing. Listed as hostesses for "R: The Party," the Misses Bush did not greet any of the partygoers. Security men whisked them away to a private room, where they stayed with their friends.

Monday they remained wordless during a "W Stands for Women" event that drew several hundred Republicans to the Waldorf-Astoria ballroom. When they walked onstage with grandmother Barbara and their aunt, all female heads in the audience swiveled as one to get a glimpse. During several speeches, they politely clapped. Jenna jiggled her foot. Her sister displayed her mother's capacity for sitting extremely still. Both laughed when their grandmother spoke of their recent trip to the Athens Olympics; as their protector, she said, she had to fend off the entire U.S. men's wrestling team, all of whom wanted to date her granddaughters.

They did not speak. "Most people are treating the Bush twins as Faberge eggs," observed pollster Kellyanne Fitzpatrick, watching the twins from the back of the room. "They're terribly shy." The campaign, she said, "is like a semester abroad for them."

By Tuesday, they talked! During a luncheon tribute to their mother, University of Texas graduate Jenna revealed a husky southern drawl. Laura Bush was such a devoted parent, Jenna said, that she once led the girls and several of their first-grade friends, all in matching pajamas, in a conga line through the family home. Barbara, the Yalie, spoke earnestly about her mother's contributions as first lady to the empowerment of Afghan women and the literacy of America's children.

So emboldened, the pair Tuesday night in prime time finally revealed important truths about themselves.

They believe Arnold Schwarzenegger has made it safe for them to marry a Democrat.

They are "not very political."

They confirm that their grandmother, Barbara, 79, is "The Enforcer Bush." When the twins wound up in the sort of ruckuses that Jenna delicately called "the spotlight," they told their father "that when we were young and irresponsible, well, we were young and irresponsible." That was a reference to what their father said when he was a candidate in 2000, when reporters asked him about a years-old drunk-driving arrest.

With quick, giggling dispatch, the girls also made reference to some issues the family-values party would just as soon reject: casual sex and vulgar hip-hop lyrics. They jokingly portrayed themselves as trying to influence policy and strategy, only to be told to check in with "Condi," "Karl" and "who is this man they call Dick Cheney?"

By the time they were done, the laughter in the hall had faded to uncomfortable tittering. Even that stalwart conservative, Weekly Standard editor William Kristol, was displeased. "I respect Laura Bush and I'm sure the twins will grow up to be lovely women," Kristol said on Fox News Channel, "but the last half-hour did not help, so far as I can tell, President Bush's campaign for reelection."

Who knows what they were thinking? Calls for comment to campaign officials, the twins' spokeswoman, the first lady's press secretary and Republican National Committee officials went unreturned Wednesday. The remarks were written by Karen Hughes, a campaign aide told the Associated Press. And they were vetted by more than a dozen staffers, another campaign official said.

But while the performance was widely panned by pundits and bloggers, the girls' remarks have delighted others.

"I loved 'em!" said former New York senator Al D'Amato. "I thought they were very relaxed," said Education Secretary Rod Paige. "Almost like veterans. They're entertaining, and it's good for the public to meet them."

He said he was pleased that Jenna had voiced her interest in teaching in a Harlem charter school, although New York magazine reported this week that she had not completed her application.

As for the girls' teasing their grandmother for being a prude, "we're in New York, so anything goes," said 19-year-old Stephen Haag at the youth convention. And standing nearby, Dan Meyers said, "I'm a big fan of theirs."

By Wednesday, the political debutantes seemed to have established themselves as being more like their father than their mother. At the women's event in the hotel, Diane Allen, a New Jersey state senator, said: "I'm so happy they didn't come in here with prim and prissy little dresses with little lace collars. Because that wouldn't have been them.

"You want reality. And the Bush girls certainly give you reality," she said, and chuckled, "just like their daddy."

For Barbara and Jenna Bush, convention week has been part family reunion, part debutante ball.Barbara and Jenna Bush at a Republican youth gathering yesterday in New York: Onstage, and back on message.