"In recent rounds of long conversations, most made it clear that they suffer a kind of survivor's guilt: they can't quite believe that for two frantic months last fall, caught in a Bermuda Triangle of a campaign, they worked their tails off to try to elect as vice president of the United States someone who, by mid-October, they believed for certain was nowhere near ready for the job, and might never be," Purdum wrote.
Following her announcement Friday, the Republican Governors Association issued a statement touting the fact that Alaska will remain in GOP hands.
"While we regret the news announced by Governor Palin today, Alaska will continue to have a Republican governor through 2010 and we are confident the state will elect a Republican in next year's election," RGA executive director Nick Ayers said.
"The RGA's focus remains firmly on the gubernatorial elections in New Jersey and Virginia this year, and the 37 gubernatorial elections that will take place in 2010. We know that winning these races is the most important task facing our Party over the next two years."
In a written statement, U.S. Sen. Mark Begich, D-Alaska, said, "I'm as surprised as all Alaskans by Gov. Palin's decision to step down with nearly two years left in her term. There was speculation she would not seek re-election, but she gave no indication of a resignation when I met with her for 45 minutes in her Anchorage office two days ago."
Former Massachusetts Gov. Mitt Romney, who was a GOP presidential candidate last year, issued a statement today, saying, "I wish Sarah Palin and her family well, and I know that she will continue to be a strong voice in the Republican Party."
Since the Republican ticket lost the presidential election, Palin has remained front and center on the national stage -- whether fundraising for the GOP, garnering publicity about her personal life as an athletic and busy, working mother, or demanding an apology from late-night TV host David Letterman for off-color comments about one of her daughters.
Palin has fought hard to maintain her image in the process, and today she said that effort has cost a significant amount of money.
"This political absurdity, the politics of personal destruction, Todd and I, we are looking at more than half a million dollars in legal bills, just in order to set the record straight," she said.
"My choice is to take a stand and effect change and not just hit our head against the wall and watch valuable state time and money, millions of your dollars, go down the drain," Palin said.
Meantime, many people have an unfavorable opinion of the McCain's pick for vice president. According to a CNN poll last month, 46 percent expressed a favorable opinion of her overall and 43 percent expressed an unfavorable opinion.
Shortly after the election, 52 percent surveyed in a Gallup poll said they'd prefer not to see Palin as a major political figure in the future, compared to 45 percent who would.
"I'm doing what's best for Alaska and I've explained why," she said.
ABC News' Kate Barrett, Rick Klein, David Chalian and Desiree Adib contributed to this report.