The telegenic Palin, who burst onto the national stage seven weeks ago, has divided conservatives - some energized by her strong stand on social issues and others embarrassed by her halting interview performances. On the campaign trail, she is a popular draw, attracting numbers that a Republican Party searching for female star power can't ignore.
The divide is clearly evident.
George Will, a prominent conservative columnist, suggested "Palin has become an even heavier weight in John McCain's saddle than is his association with George W. Bush."
Indeed, a poll released this week by the Pew Research Center found that 49 percent of voters had an unfavorable opinion of Palin, compared to 44 percent who viewed her favorably. Pew also found that unlike past vice presidential choices, opinions of Palin mattered to the ticket.
And public opinion about Palin is slipping, according to a CBS-New York Times poll released Thursday. It found that the number of voters who think she is not prepared has grown from 50 percent to 59 percent in the last month.
None of that is apparent as Palin campaigns across battleground states in the closing days of the presidential contest. She drew huge crowds to a rally in southern Missouri on Thursday and 16,000 jammed in to see her Wednesday night in Jeffersonville, Ind., many wearing "Sarahcuda" T-shirts and buttons saying "I'm a bitter gun owner, and I vote."
Pell Blakeman, a Palin supporter who now calls himself "Pell the Electrician" in honor of the infamous Joe the Plumber, captured her appeal this way: "She just connects with the people. She's doing a fine job and she'll make a fine president one day."
Palin's future will be a top item on the agenda at a meeting of national conservatives scheduled next Thursday outside Washington. Participants in the meeting have declined to offer many specifics but said Palin's role in the conservative movement, either as vice president or as a 2012 contender if the GOP ticket loses, will be discussed.
To that end, Palin has begun to develop a national political identity that is separate from McCain's.
She's given three policy speeches in the last week, on energy independence, special needs children and the ways in which women are affected by national tax policy. She announced her support for a constitutional amendment banning gay marriage despite McCain's long-standing opposition to such a measure. And she has publicly questioned some of the McCain campaign's tactics, like the use of robocalls and the decision to pull resources out of Michigan.
Such departures from the script have irked some of McCain's advisers even as the Arizona senator insists he has no problem with Palin asserting herself.
"Sarah's a maverick, I'm a maverick. No one expected us to agree on everything," McCain said on "Larry King Live" Wednesday, adding, "We share the same values, the same principles, the same goals for this country."
If the Republican ticket were to win next Tuesday, Palin would instantly be viewed as a GOP nominee-in-waiting no matter what her stated intentions. She'd also be the most prominent and popular conservative in McCain's sphere - a powerful role, given many conservatives' lukewarm view of McCain.
"You have various legs to the Republican stool, and she'll be a feisty spokeswoman for that part of the party," Republican strategist William O'Reilly said of a potential Palin vice presidency.
But with Democrat Barack Obama leading in the polls, McCain aides are second-guessing many decisions made during the campaign, including Palin's role.
She was poorly vetted for the job, leading critics to say McCain had botched his first major decision as a presidential nominee. And aides are distraught over how Palin's initial rollout turned sour after her well-received speech to the Republican National Convention in August.
In the days that followed, Palin was shielded from the press except for a few cringe-worthy TV interviews in which she was hard-pressed to name a newspaper she reads and said Alaska's proximity to Russia gave her insight into that country's affairs. The interviews helped fuel Tina Fey's widely viewed "Saturday Night Live" impersonations of Palin as charming but clueless.
"I think she may have been ill-served by staff who sequestered her after the convention and gave the Democrats a chance to define her," New Hampshire GOP chairman Fergus Cullen said. "That may have lasting political consequences for her past election day."
Palin's reputation came in for another hit after the Republican National Committee disclosed it had spent about $150,000 at pricey department stores and boutiques to buy clothes for her and members of her family. Palin defended herself as a frugal shopper and called the purchases part of the stagecraft of running a national campaign, but the flap helped tarnish her image as a champion of the middle class.
But Palin's strongest support still lies with grass roots voters, many of whom cite her popularity and executive experience in Alaska as evidence that she could step into the presidency once day.
"I think she's the best thing that's happened to this campaign," 20-year Navy veteran Bill Costello said at the Missouri rally Thursday. "Me and my particular clique - we aren't voting for John McCain, we're voting for Sarah."
Associated Press Writers Liz Sidoti in Washington and Jim Salter in Missouri contributed to this report.