FAMILY CONSIDERATIONS

Former Alaska Governor Sarah Palin speaks at a Tea Party Express rally in Manchester, New Hampshire September 5, 2011. [Photo/Agencies]

In her letter, Palin cited family considerations as playing a major factor in her decision. She has felt the US news media has gone too far in covering her family, such as the drama involving her daughter Bristol's tempestuous relationship with the father of her child, Levi Johnston.

She made clear she would turn her attention toward recreating a role she carved out for herself in the 2010 congressional elections, helping elect Tea Party conservatives to Congress, state governorships and the White House.

"I believe that I can be more effective and I can be more aggressive in this mission in a supportive role of getting the right people elected," she told Levin.

Palin's star had faded since her opening days as McCain's vice presidential nominee in 2008 when she burst onto the scene as a relative unknown and quickly became a conservative star and promoted herself as a "mama grizzly."

She has been polling far behind the main challengers for the Republican nomination and most Palin-watchers had long since concluded that she was not going to run based on a series of equivocating statements.

The only woman in the 2012 race now is Minnesota Congresswoman Michele Bachmann, who is popular with the same social conservatives who find Palin an electrifying presence.

There seemed to be no temptation by Palin to run for president as a third-party candidate.

"I would assume that a third party would just guarantee Obama's re-election and that's the last thing our republic can afford. So the consideration is not there for a third party, no," she told Levin.

Costas Panagopoulos, a political science professor at Fordham University, said he expects Palin to be a factor in the 2012 elections.

"She has a very dedicated following and a knack for staying relevant in politics, even when she herself is not a candidate," he said.