I just want to clear up one little bit of information here. By law, membership dues cannot be used for lobbying or political contributions, so the idea of "purchasing a membership to protect your rights" is misleading. Your membership dues are for the purpose of scoring your races, and associated purposes, and for putting your name on their mailing list for donation requests to their lobbying and political arms, and so that they can claim the clout of having "X million members". If you want to "protect your rights", then give directly to their lobbying branch, because "protecting your rights" is false justification for overpriced membership dues for AMA scoring of competitions and is the leading cause for a reduction in memberships. While their effectiveness in lobbying to protect our rights is debateable, (and Im personally less than enthusiastic), if that is what you support in the AMA, pushing memberships does not help that cause.
Hi membership dues usually do not increase revenue as they tend to drive away all the infrequent or one time racers, and discourage would be potential new racers from ever trying it out.