I don't think conservatives ever have been the majority anywhere. I tend to concur with the thesis that the Right is better organized and more committed than the left. The left gets mad about an issue and can turn out its hordes for a short time. The Right endures.
Great thoughtful article, as were the others in the series. I have to wonder about the "movement," though. Americans' conservatism is more instinctual and almost inborn. A movement can support that heartfelt conservatism, but when it tries to lead or dictate it starts to look just like another political machine and loses support among the public. When political answers and opinions are preprogrammed and scripted, people who'd be around in a real crisis may find it to be overkill and lose interest.
The great strength of 20th century conservatism was that the liberals had been so much more ideological. It seemed like they went to the same schools, had the same goals, and parroted the same talking points. By contrast, conservatives were more Main Street and closer to ordinary people. The rise of an organized conservative movement or establishment with its own ladders of advancement, enforced political orthodoxies, and special interest connections may mean a loss of support among instinctual small "c" Main Street conservatives.