At first, some interpreted the surprise announcement by Alaska Governor Sarah Palin that she was stepping down as being only the beginning of her political aspirations.

But UNC Professor Emeritus William Leuchtenburg believes it probably is the end.

Palin abruptly announced she was giving up her job as governor on Friday afternoon, which shocked many within the Republican party and even members of her own family. Palin and her staff kept her future plans shrouded in mystery, and it was unclear if the controversial hockey mom would quietly return to private life or begin laying the foundation for a presidential bid.

The announcement came after a stormy week for Palin, which included negative pieces in Vanity Fair Magazine and the CBS Evening News. Leuchtenbuerg says Palin's resignation, timed on the eve of the July 4 holiday when many Americans had already begun a three-day weekend, seemed designed to avoid publicity.

He believes there may be something bigger on the horizon.

Pam Pryor, a spokeswoman for Palin's political action committee SarahPAC, said the group continues to accept donations on its Web site, with an uptick in funds after Palin's announcement.