NEW YORK - President Obama shows "a stark lack of faith in the American people." JFK "seemed to want to run away" from his faith, while Mitt Romney "forthrightly embraced it."

American Idol

contestants suffer from "the cult of self-esteem."

Sarah Palin offers these and other observations in her new book, America by Heart: Reflections on Family, Faith and Flag, billed as a tribute to American values.

The book comes out Tuesday. The Associated Press purchased a copy early.

Palin's first book, the memoir Going Rogue, has sold more than two million copies.

Palin's potential presidential ambitions have been the subject of chatter, with her every remark parsed for clues.

The former Alaska governor said this week she believed she could defeat Obama if she were to challenge him in 2012. Count Vice President Biden among those who aren't taking her for granted.

"I don't think she could beat President Obama," Biden said Friday in an interview with MSNBC's Morning Joe. "But, you know, she's always underestimated."

She doesn't detail her plans in the book but speaks of a need for new leaders.

"We're worried that our leaders don't believe what we believe, that America is an exceptional nation, the shining city on a hill that Ronald Reagan believed it is," she writes.

In a chapter on faith and public life, Palin addresses John F. Kennedy's noted speech on religion during the 1960 campaign - a speech many saw as key to countering sentiment that his Catholic faith would hold undue sway over him if he became president.

"I am not the Catholic candidate for president," Kennedy said. "I am the Democratic Party's candidate for president, who happens also to be a Catholic."

Palin writes that while growing up she was taught that JFK's speech reconciled religion and public service without compromising either. But revisiting it as an adult, she says, she realized that Kennedy "essentially declared religion to be such a private matter that it was irrelevant to the kind of country we are."

She praises former Massachusetts Gov. Romney, a Mormon, for not "doing a JFK" during his campaign for the 2008 GOP nomination. "Where Kennedy seemed to want to run away from religion, Mitt Romney forthrightly embraced it," she writes.

Historian Ted Widmer, who included the JFK speech in a Library of America anthology of American oratory, said Palin's comments put "a negative spin on what was interpreted at the time as a sensible and uplifting message."

On a pop-culture note, Palin takes aim at American Idol, even though her daughter Bristol is in the thick of a much-scrutinized run on a similar show, Dancing With the Stars. Palin calls Idol's contestants "talent-deprived."

But Simon Cowell, the acerbic judge who left the show? He is "almost alone in his willingness to tell hard truths."