Sarah Palin, Newt Gingrich, Michelle Bachmann, Donald Trump, and Ron Paul will not win the GOP nomination. In fact, Palin and Bachmann aren't even formally running yet.
Newt Gingrich won't pass the conservative test because of his divorces and is reviled by liberals for his witch-hunt against Clinton, which means him getting the nomination will mean an instant loss for the GOP.
Donald Trump is a good businessman, so he would be good with regards to the economy, but he has absolutely no experience with governing, which is vastly different from directing a business. For example, a CEO doesn't have to deal with a legislature in order to enact policies. So he may actually try to extend executive authority. This is actually an issue that Florida governor Rick Scott is dealing with now.
Ron Paul, while a favorite of the Tea Party crowd, won't win the GOP nomination either. While people distrust the government, they also distrust mega-corps too. The government serves as a check against big businesses. I think that while people favor certain planks of his platform, they are uncomfortable with his platform as a whole. Therefore, he won't get the nomination either.
Mitt Romney would be able to attract moderate Republicans and moderate Independents and even conservatives Democrats. After all, he's a successful businessman and the economy is where President Obama is the weakest. He also has governor experience which makes him well suited to the Presidency. However, the fact that his Massachusetts health care plan was a model for the Democratic health care plan doesn't help him with the far-right, and neither does his changing attitudes concerning abortion. However, those stances are what makes him so favorable in the general election, but not the primary.
To be honest, I don't know much about Tim Pawlenty, John Huntsman, or Mitch Daniels. What little I've read up on them to make this post, it seems to me that John Huntsman is too unknown and possibly too centrist to win the primary.
Which means it'll likely come down between Tim Pawlenty and Mitch Daniels. Between those two, Mitch Daniels probably has the edge because of social issues. Daniels passed laws to make abortions more difficult to get and has reduced funding to Planned Parenthood. Tim Pawlenty, however, has focused more on economic issues.
So among all those options, it might be Mitch Daniels who is the most likely to get the nomination.
