"I don't minimize how she is revered by the Republican right, nationally," Moore said.
"But at the end of the day, to become president she's going to have to convince that 5 percent or 10 percent of people in the middle, ideologically, that she and McCain didn't convince last year, and those people are not going to be impressed that in her first four years sitting in high office she quit halfway through."
Moore said Palin would have been a strong favorite to win a second term, even though her popularity has fallen from past heights. Her approval rating is still in the 50 percent to 55 percent range, the pollster said.
Many Alaskans believed she would not seek a second term, but probably would wait until spring to make her announcement to avoid being a lame duck.
Friday's announcement came out of the blue. "It's a gob-smacking, jaw-hit-the-ground, total kind of surprise," Moore said.
Stuart Rothenberg, an independent analyst and publisher of the Rothenberg Politi cal Report, said Palin's announcement won't improve the perception held by some of her as a lightweight.
"It's very, very curious," he said. "There almost has to be more to this because people don't just step down from a state's top office in the middle of a term."
"I always thought after the [2008] race, the thing she needed to do was go back to Alaska and be substantive, show she's got a grasp of government and work for the folks back home. This seems to be the exact opposite," Rothenberg said.
But Scott Reed, a Republican strategist who is unaffiliated for 2012, said Friday's announcement could be a good thing because it allows Palin to turn the page and start rebuilding her image.
He described the Vanity Fair article as a "hit job" that showed Palin that she had to shake things up.
Stepping down "allows her to begin to draw a new narrative on herself," Reed said.
"If anything," he said, this "allows her to have a brand-new day, a fresh start, and she can shake all these cobwebs from the last campaign and her term as governor and start over."
