They structured the caucuses such that independents had more influence earlier in the cycle thereby removing the most conservative candidates early. I have every confidence Thompson would have done extremely well in the south. Unfortunately he didn’t see it that way because of the early returns.
The GOP selection process should be reserved for GOP members. I also suspect there were a few Dem’s registered as Republicans causing mischief as they are desperate for the white house. Not recognizing there willingness to game the system would be naive (just look at the participation they are seeing at their caucuses).
It might be possible to do this in more states than do it now, but at least a dozen states have no party registration. That would make it impossible to restrict the primary to Republicans.
I might vote in our RAT primary next week since there is no point voting in the GOP primary.