Sarah Palin's magical mystery bus tour stormed into Philadelphia Tuesday afternoon, chased down the Schuylkill Expressway by as many as 15 news media vehicles while helicopters tracked the ragged caravan from the sky.

Pushing through crowds of onlookers and reporters, Palin and her family took a half-hour speed tour of Independence Hall and the Liberty Bell pavilion. When the chaos subsided, little more was known - about the purpose of the tour, Palin's political intentions for 2012, or even where she was headed next.

"I don't know if I'm running yet," Palin said as she hustled to a silver SUV waiting on South 5th Street, engine running, about 1:45 p.m. She said she was having a great time. Palin stopped to sign a proffered baseball, ducked into the SUV, and was gone.

As it turned out, the next stop was New York. Palin reportedly was to visit the Statue of Liberty and Ellis Island, and went out for a pizza dinner with fellow reality-TV star Donald Trump, who briefly presented himself as a possible candidate for the Republican presidential nomination.

In Center City, dozens of reporters and photographers chasing a rumor ran from one end of the Liberty Bell pavilion to another, only to find that the former Alaska governor's bus had pulled up behind Independence Hall. "Sarah went that way!" a group of teenagers on a school trip yelled, helpfully pointing. When Palin and her group emerged from the building where the Declaration of Independence and Constitution were crafted and started to cross Chestnut Street, the media mob charged down the sidewalk, scattering several groups of elementary school students.

"Watch the children!" a frightened chaperone yelled. "Don't step on the children!" (No injuries were reported.) The crush of people slowed the Palin family's progress, however. Annoyed daughter Piper, 10, pushed some camera lenses away from her.

Earlier in the day, Palin slipped out of her Gettysburg hotel while reporters encircled the idling bus, heading to the battlefield for a private tour.

Palin launched her odd "One Nation" tour on Sunday, at a motorcycle rally of veterans in Washington, then on Memorial Day hit the National Archives; Mount Vernon, George Washington's home; and Fort McHenry in Baltimore, before heading north for Gettysburg.

The strange trip has no public schedule - information about stops is posted on the SarahPAC website only after they are made - turning the political press into paparazzi who must stalk the bus to cover Palin, who seems to enjoy stirring up the frenzy.

"I want them to have to do a little bit of work on a tour like this, and that would include not necessarily telling them beforehand where every stop is going to be," she told Fox News' Greta Van Susteren on the bus Monday. "The media can figure out where we're going if they do their investigative work."

Jackie and Jason Block, of Cincinnati, decided to see Gettysburg and Independence Hall before heading home from a wedding they had attended in New Jersey, only to find Palin had the same itinerary.

"She's been toying with us all weekend," said Jackie Block, 21, who waited to get a glimpse of Palin on Chestnut Street. "I've always been a fan. She holds the same moral values as I do, and her family is close to the way I was raised. I wish she would run for president; she's a real go-getter."

Jason Block, 27, a veteran of Iraq and Afghanistan in the Army's 82d Airborne Division, likes that Palin "supports the troops."

Sue Hunter, of Northeast Philadelphia, was in Center City having lunch with a friend and hoping to get a glimpse of Palin. She was a few moments too late.

"I just respect her beliefs - she's Christian and godly, and she's a strong woman," Hunter said. "I just don't know if she's strong enough to beat Obama, that's what I'm worried about."

Janice Rottenberg, who just graduated from University of Pennsylvania with a degree in political science, got Palin to sign a copy of her new book, America by Heart.

"I'm a Democrat, pretty hard core," said Rottenberg, 21, of South Bend, Ind. "Isn't she just transfixing? How is this stuff even happening?" She said she thought Palin's strategy of handling the media was brilliant.

"If you don't make your intentions clear, if you don't give enough information, you get an hour of talking heads debating where your trip will take you," Rottenberg said. "If you put it out the details... it's on to the next story."

Palin has said the PAC-financed bus trip is just a family vacation to historical sites, but nobody really believes that. It comes at a time when the 2008 Republican vice presidential nominee has drifted from the center of the national political conversation. The trip - and the impending release of a positive biographical film on Palin - reignited talk she may get into the GOP race.

Palin would no doubt upend the race if she did - she has a core of devoted followers and is popular among social-issues conservatives - but some recent polls suggest she would have a hard time winning the nomination, and little chance of winning a general election against President Obama.

In late April, Gallup asked Republican voters which potential candidate they would definitely not vote for; 37 percent said Palin, by far the most toxic name on the list. Sixty-five percent of surveyed registered voters overall, who included Democrats and independents, said they would never vote for her.

Contact politics writer Thomas Fitzgerald at 215-854-2718 or tfitzgerald@phillynews.com. Read his blog, The Big Tent, at www.philly.com/BigTent.