ST. PAUL, Minn. — The McCain campaign is showing signs of being spooked by the press frenzy about Governor Palin’s family, abruptly canceling a scheduled appearance by the presumptive vice presidential nominee, moving to keep the candidate under wraps until today’s prime-time speech at the Republican National Convention here.

The organizers of the Republican National Coalition for Life’s cocktail-buffet reception told The New York Sun that the McCain campaign called them late Monday evening to cancel the appearance of the Alaska governor. Mrs. Palin did meet behind closed doors with leaders of the American Israel Public Affairs Committee.

While it is somewhat customary for a vice presidential nominee to be shielded from the press at a political convention until his or her big speech, Mrs. Palin’s candidacy presents a new kind of challenge for the campaign. The Republicans lost nearly two days of their convention because of Hurricane Gustav. Now the disclosure that Mrs. Palin’s 17-year-old daughter, Bristol, is five months pregnant and will be marrying the father of the child has threatened to upstage the McCain campaign’s message. NBC News first reported last night that Levi Johnston, the father-to-be, will be joining the Palins here today.

The founder of Eagle Forum and the organizer of the Coalition for Life Palin event, Phyllis Schlafly, Monday told The New York Sun that she “had no idea” why the McCain campaign yanked Mrs. Palin from her speaking engagement. The Alaska governor had been booked two months in advance for the $95-a-ticket reception.

“I was notified at 10 p.m. last night,” she said. “They did not want to have her have any other events, and they wanted her to rest up for her big event tomorrow night.” Mrs. Schlafly said she thought the decision was “dumb.” “Look at this audience. It would have been a tremendous way to charge her batteries and show Governor Palin that the pro-life movement was a thousand percent behind her,” she said.

The founding executive director of the Christian Coalition, Ralph Reed, said that it was disappointing that Mrs. Palin did not make it to the reception, but nonetheless he understood. “As a general rule, I would have loved to have had her here. The reality is they want to save her big moment for tomorrow night, because they are running the campaign.”

Mr. Reed said that Bristol Palin’s decision to marry and give birth to her baby was energizing the conservative base of the Republican party. “The fact that she is marrying the father of the child and she is having the baby is only going to endear this candidate further to the grassroots social conservatives,” Mr. Reed said.

The program officer for the National Campaign to Prevent Teen and Unplanned Pregnancy, William Albert, said that his organization respected the privacy of the Palins. But he added, “There are precious few parents who would counsel their children to begin a family at age 17. We don’t know the circumstances under which this young lady became pregnant. But here is a practical application of all of this. This provides a unique opportunity to sit down around the kitchen table and talk to their kids about these sets of issues.”

While the Alaska governor has been kept out of the public eye, she has met with some key interest groups. According to one Republican source familiar with the meeting, Mrs. Palin was introduced to Aipac leaders here by Senator Lieberman, the independent Democrat from Connecticut who endorsed Senator McCain last night.

Mr. Lieberman said, according to this source, that he remembered his big week eight years ago when he was tapped by Vice President Gore to be the 2000 Democratic nominee’s running mate, and how he was so focused on his speech before.

This source said Mrs. Palin “talked about her personal connection to Israel that she has had since she was a young child, it has been part of her views and how important this small country was for so many people for so many reasons.” This source also said, “She subscribes to Senator McCain’s ‘never again’ policy,” a slogan popularized after the Holocaust and a promise never to allow genocide to go unchallenged. Mrs. Palin also said her mother had recently traveled to Israel, according to this source, and that she displayed an Israeli flag in her office in Juneau.

The Alaska governor with no record on Middle East foreign policy impressed Aipac. “We got a good productive discussion on the importance of the U.S.-Israel relationship, and we were pleased that Governor Palin expressed her deep personal commitment to the safety and well-being of Israel,” a spokesman for Aipac, Joshua Block, said.

He added, “Now that both Democrats and Republicans have determined their respective tickets, Aipac is pleased that both parties have selected four pro-Israel candidates, and in doing so they have reaffirmed the broad bipartisan support that exists in our country for a strong U.S.-Israel relationship.”