Madalyn Ruggiero/AP

Sarah Palin ended speculation surrounding her 2012 political ambitions when she announced she will not be running for president this year.

"After much prayer and serious consideration, I have decided that I will not be seeking the 2012 GOP nomination for President of the United States," Palin said in a letter to supporters obtained by ABC News.

"As always, my family comes first and obviously Todd and I put great consideration into family life before making this decision. When we serve, we devote ourselves to God, family and country. My decision maintains this order.

"I believe that at this time I can be more effective in a decisive role to help elect other true public servants to office - from the nation's governors to Congressional seats and the Presidency."

While the former Alaskan governor did not say who she would endorse, she said she planned to play a role in national politics.

"I will continue driving the discussion for freedom and free markets, including in the race for President," she wrote.

"In the coming weeks I will help coordinate strategies to assist in replacing the President, re-taking the Senate, and maintaining the House."

Republican party officials have predicted for months Palin wasn't running because she'd be forced to give up a lucrative speechmaking business earning her millions of dollars a year.

"The tipoff was that she wasn't doing any homework on the issues," explained a senior Republican with close ties to Palin. "As Rick Perry has learned, you have to be prepared in debates to talk about stuff you don't know, and she wasn't preparing."

Another GOP consultant said Palin's diva reputation tempted her to run, but a series of recent polls have shown a majority of Republican voters don't want her to be the party's candidate.

"Her negatives are high and she turns off independents," the consultant said. "Obama would have a field day running against her."

A new Washington Post/ABC News poll found only 31% of Republican primary voters wanted her to run for President. Two-thirds of those surveyed said she shouldn't get into the race.

Palin's decision to stay out, a day after after New Jersey Gov. Chris Christie said he would also not run, means the field is Republican candidates is likely set.