Hoosier Advocate has the results from a GOP poll (one of the candidates' internal polling) that indicates that with a little under a month to go, it is a two horse race. The results are:
Dan Coats - 29%
John Hostettler - 26%
Marlin Stutzman - 18%
Don Bates, Jr. - 5%
Richard Beheny - 3%
Undecided - 19%
Some might say that Stutzman is in it because there are 19% undecided, but it is unreasonable to think that more than half of the Undecided will break to Stutzman at this late date. An observer at Hoosier Access accurately points out, the contenders are splitting the vote giving Dan Coats the advantage. I disagree with the analysis that Coats is a "moderate", but there is no question that a Hostettler or Stutzman is newer blood that is able to pull off a more conservative rhetoric at this stage of the game.
If you have the time, you can view a recent debate between the 5 candidates at Hoosier Access. From a content perspective, there is really not that much difference between any of the candidates. The question in my mind is what will be their relative effectiveness in the Senate.