Conventions and their Moderate Speakers

People said that the Democratic delegates were far more liberal than the Convention presented. They shifted toward the center. Now the same is being said about the Republicans, especially in terms of their speakers. I would think this is obvious, but it seems to confound many observers. The activists of both parties will by necessity be less centrist than the country. For one thing, the parties are more ideological, as Jim jeopardize and Zell Miller illustrate. This is a problem for the two-party system, but parties don't represent ideological diversity any more. So who will take the time and trouble to participate in political campaigns? Who will go to conventions? The ideologically committed. Ideologically committed centrist don't have a party. They cross back and forth, they are swing voters. So the parties, with a base on the left and right then reach out to the center to win them over to their side for this or that election. So of course parties will put on a more moderate face as they reach out to the center. How else could it be? Any discussion that fails to recognize this seems to me to be fundamentally confused.