If there is debate, it has to be according to a common framework of deliberation, or else there is only force. If the claim has to do with what is important to the mainstream of American history, the attempt is to show that the material advocated is more central than has previously been recognized. The fact that there might need to be debate does not, itself, disprove the objectivity of the contention, it merely shows that some things are a matter of complex judgment, rather than simple measurement, and may therefore take time to deliberate about.
The fact that "all reasonable people" might not agree immediately on some thing which may entail experience and long reflection to see do not therefore mean that the thing is subjective. When I directed plays I "saw" a lot of things my actors could not see, and which I could only partially explain, and never in a manner that would appear to be more than opinion. Only after the things were incorporated into the performance, and worked, and made things better, could they see that I knew what I was talking about. |