I think that you are right about that, but I wouldn't be so quick to put them in Akin's column. Most will just not cast a vote in this particular election. You are being too optimistic by half.
If you can find the internals of that Rasmussen poll post them and ping me. I have a hard time believing that she has 49% support in that poll which would require atleast half of Missouri independents most of whom are ABMs and ABOs.