Palin is a divisive figure in American politics. She could never rally enough moderate and independent voters to achieve victory. Regardless of your own opinions about palin, the question is could she win. The answer is no, she could not win wide support and the money needed to defeat a democratic star like Hillary and the Clinton political machine. The wild card is Hillary's health, she is old and has had health problems... It could be her undoing.
Palin helped McCain energize conservatives and some independents, but she was a albatross when it came to questions of foreign and national security-Iraq, Afghanistan, Syria. Yes, as the former commander-in-chief of the Alaska National Guard, she had some experience, but she comes across as unintelligent. Also, the DNC and the Clinton campaign, along with the media will find video and statements from Palin ranting and it could cost her some states.
Sarah Palin is popular only because of McCain. Her views are so acerbic, and populist that her candidacy is veneer meant to give her position the illusion of respectability. She ha son policies and at this point, just wants money - more power to her. If she seriously ran for President, Hillary would monkey stomp her. Whatever ones opinion of Hillary, she is an incredibly smart and tenacious woman - few people of any gender can match her sheer grit.
Sarah Palin does not have the qualifications, honor, dignity, experience, and promise of Hillary Clinton. Palin will surely have many supporters, primarily Tea Party members. However, Clinton would win in a landslide. First, she was the First Lady, which already makes her a prominent figure. Then she became a Senator, which makes her experienced. Then, she became Secretary of State - a good one, too. Palin, an unexperienced, infamous politician, does not have the capacity to challenge Clinton, a qualified, experienced veteran of the political world.