I have learned two things since then:
1) One doesn't have to have donated: political parties will routinely attempt
to touch one's pocket if they have but a glimmer of hope of shared interests.
(no doubt to earn the postage and salaries with which to solicit yet more...)
2) Even if you've donated merely a small sum, it has to be recorded: the
reporting limits for donors might be hit by the accumulation of several small
donations.
I hope parties can decline donations, so as to avoid having to match up
records for "Geo. H. Qwerty, Underwater Basket Weaver: $5" with "G. Hbar
Qwerty, submarine basketry: $5", etc.
-Dave