This is a fight over 49 GOP delegates or 4% of the 1144 needed to win the nomination. In 2008 McCain won with 1455 delegates as opposed to his nearest competitor Huckabee with 270 delegates. So in the overall scheme of things these 49 delegates probably won’t make any difference in the overall outcome. What does matter is the primary voters in VA are being limited as to their choices, but that’s the process established by their governing bodies.
They are apolitical organization and are free to change their rules at amy time. Pressure could be effective, especially if applied towards Gov McDonnell and his future politcal aspirations.