Updated

DES MOINES, Iowa -- Former Alaska governor Sarah Palin is on a roll: Her political endorsements have helped propel upstart Republican contenders to victory in recent primaries, her cable TV show makes its debut in November, and now she's off to Iowa, a state that has made and broken its share of presidential campaigns.

The 2008 Republican vice presidential candidate will be the big draw at Friday's Reagan Dinner in Des Moines, the Iowa Republican Party's biggest fundraiser, and the question that will be on everyone's mind is whether she'll run for president in 2012.

Iowa, home to the nation's leadoff presidential caucuses, can be tough terrain for celebrity candidates. Those who try to ride their fame to victory in Iowa without organizing a grass-roots campaign often find themselves on the outs.

Take John Glenn. The former astronaut and senator drew huge crowds and intense attention here when he sought the Democratic nomination in 1984 -- but he got just 4 percent of the vote.

"They were coming out to see John Glenn the astronaut, not John Glenn the Democrat running for president," said veteran Republican strategist Eric Woolson.

If she runs, Palin would start with strong appeal among the social and religious conservatives who play a crucial role in Iowa's Republican politics. But that appeal wouldn't necessarily last if it's not backed up by a strong effort to reach out to caucus voters, said Steve Scheffler, head of the Iowa Christian Alliance.

"The track to success in Iowa is slogging around all the small towns in bad weather and sleeping in downscale motels because that's the best in town," said Rich Galen, a Republican strategist based in Washington. "That certainly doesn't seem to fit the Palin theory of how she should conduct her life."

A Palin candidacy also would test Iowa's glass ceiling. Just ask Hillary Rodham Clinton, who came in third in the 2008 caucuses, how tough the state can be for a woman. Iowa is one of two states -- Mississippi is the other -- that's never sent a woman to Congress or elected a woman governor.

Palin is far from alone in taking early steps to court Iowa activists. Former House Speaker Newt Gingrich has made multiple trips to the state, Minnesota Gov. Tim Pawlenty has put a staff member in Iowa and former Massachusetts Gov. Mitt Romney, New Jersey Gov. Chris Christie and former Sen. Rick Santorum of Pennsylvania all have visits in the works.

Palin has been coy about her presidential intentions and masterful at keeping her name in the news since she abruptly resigned as Alaska's governor in 2009. She's mixed political fundraisers and candidates' campaign events with speeches in which she commands fees as high as $100,000.

Her memoir, "Going Rogue," was a best-seller. Her new book, "America by Heart: Reflections on Family, Faith and Flag," will be published in December.

Her favorable ratings have been slipping all year, in recent weeks dropping below 40 percent for the first time, in the latest Associated Press-Gfk poll. Forty percent now have a very unfavorable rating of Palin. But among Republicans, about two-thirds give her positive marks and one-third view her very favorably.

Palin cheered Tuesday's political upsets by candidates affiliated with the independent, anti-tax tea party movement, including Christine O'Donnell's surprise win in Delaware over a moderate veteran congressman for a U.S. Senate seat. Palin also endorsed former New Hampshire Attorney General Kelly Ayotte, who won that state's Republican nomination to the Senate.

Fresh off those two big wins, Palin this week called for the Republican "political machine" to put aside differences within the party and home in on Democrats, whom she said have a "weakened leftist party."

Palin, whose Twitter and Facebook pages are required reading in political circles, also took some jabs at the media for all the interest in her wardrobe and gestures rather than her record.

"According to the media," she said, "I was plucked from obscurity while staring at Russia from my house."

Not that Palin is averse to using the media for her own purposes. Coming up in November on cable TV's TLC is "Sarah Palin's Alaska." Mark Burnett, who created reality TV's "Apprentice" series, describes this new project as "a really nonpolitical show, a show about Alaskan adventure."

A nonpolitical show that, no doubt, will only boost Palin's political visibility. It likely will only take her so far in Iowa, though.

Iowa strategist Mark Daley, who worked for Hillary Clinton's campaign, said the lesson from the 2008 caucus campaign is that Iowa is all about grass-roots organizing.

"There's definitely no question that while rock star status helps you draw a crowd, you're going to have to go to the Pizza Ranch in Algona," said Daley. "Voters take a very long time to make up their mind and they expect to meet with the candidates because they have for decades."

Richard Schwarm, former chair of the state Republican Party, said Palin's celebrity status does help.

"A lot of people have to work hard to get the media to pay attention, to get the precinct captain to take you seriously," said Schwarm. "It gets your foot in the door to get that attention, but it's a long process."