Former Alaska governor Sarah Palin (R), who has been largely out of the public eye through much of the spring, will reemerge Sunday as she begins a national bus tour that will put her back in the spotlight and no doubt renew speculation about a possible presidential bid.

The tour, the first of what will be a series of such journeys over a period of weeks, will start on Sunday in Washington at the annual Rolling Thunder motorcycle rally and work its way north along the East Coast. She will visit other parts of the country later, stopping at symbolically important sites in the nation’s history.

Palin advisers declined to provide additional details of the itinerary, but the trip will include a stop in New Hampshire. They also would not engage questions about whether the tour is a precursor to a presidential campaign. Asked the purpose of the trip, Tim Crawford, the treasurer of Palin’s PAC, said, “Because she wants to see how this nation was built and get fired up about that.”

On her Web site, Palin wrote: “I’ve said many times that America doesn’t need a ‘fundamental transformation,’ instead we need a restoration of all that is good and strong and free in America! So, together let’s prepare ourselves for the days ahead by reminding ourselves who we are and what Americans stand for.”

Up to now, most Republican strategists have assumed that Palin, the Republican vice presidential nominee in 2008, would not seek the presidency in 2012. Many still doubt she will. At a time when the GOP nomination battle has moved into a new phase, Palin has been mostly absent from the scene. She is also weaker politically than she was at the start of the year.

She has made no trips this year to Iowa, New Hampshire or South Carolina, the three most important early states on the nomination calendar. She also is not said to be reaching out to potential fundraisers or to grass-roots activists.

“If [Palin] is doing any outreach at all, it would have to be totally under the radar and not with the traditional activist crowd,” said a top Iowa GOP strategist who spoke on the condition of anonymity to be candid.

Still, Palin remains the most notable Republican still on the sidelines and the announcement of her bus tour set off a predictable media frenzy that guarantees her significant coverage as the trip begins.

The announcement comes at a time of activity around Palin. There have been reports that she and her husband, Todd, may have purchased a $1.7 million house in Scottsdale, Ariz., which would be a more convenient location to base a national campaign than Alaska. Palin advisers declined to comment on the matter.

Earlier in the week, Real Clear Politics reported that a full-length documentary by conservative filmmaker Stephen K. Bannon charting Palin’s political rise in Alaska will debut next month in Iowa, Nevada, New Hampshire and South Carolina — the four opening states of the presidential nominating process.

Palin’s team initiated the film. Bannon said in a phone interview on Thursday that he made the movie at his own expense, that he did not interview Palin for it, and that the former governor and her team had no editorial control over it.

He predicted that audiences will come away with a new impression of the former governor. “People may say a lot of things about Governor Palin and Sarah Palin, but I guarantee when they come out they will not say she’s not smart, she’s not tough and she’s not dedicated,” he said.

A Gallup poll released Thursday showed Palin with 15 percent among Republicans and GOP-leaning independents. That put her second, behind former Massachusetts governor Mitt Romney, who was at 17 percent. The organization said she and Romney, who has not officially declared a candidacy, have benefited most from the decision by former Arkansas governor Mike Huckabee not to run again in 2012.

Palin has long maintained that it is too early to make a decision about running, and those who know her have said she could wait longer than most other Republicans and still have the capacity to raise money more quickly than most of her rivals.

In her public appearances this spring, Palin has challenged party leaders in Washington to hold firm in budget talks with the White House and Democrats. At a rally in Wisconsin, taking inspiration from the University of Wisconsin women’s hockey team, she said the party leadership “needs to fight like a girl.”

More recently, Fox News host Greta Van Susteren asked about Palin’s possible desire to run. “I have that fire in my belly,” the former governor replied.

Palin was hurt politically by the reaction to a video she released in the aftermath of the mass shooting in Tucson that killed six and wounded 13 others, including Rep. Gabrielle Giffords (D-Ariz.).

Palin accused those who said that she and other conservatives had contributed to a climate of violence of having engaged in a “blood libel,” a slander of Jews that is centuries old.

Palin’s favorability ratings declined after that. In a Washington Post-ABC News poll in March, her unfavorable rating was higher than for any other prospective GOP presidential candidate in the rankings.

Staff writer Chris Cillizza contributed to this report.