Some big issues are deal killers, abortion and amnesty, because they are evidence of a world view that we cannot support.
Agreed. Every one needs to sit down and determine what their 100% candidate would stand for and assign percentages to those positions adding up to 100%. Then you determine what the passing score is. If 100% is your passing score, you need to run yourself because no one will live up to your standards.
I agree that amnesty and abortion are items which would kill a conservative candidate, so I would assign each of them 20% and require an above 80% to support.