Don't ever make the mistake I made and send too much at once because then they move you onto another list altogether. I used to get letters requesting decent amounts, but once when I just got paid on a big job I decided to send in a large (for me) donation to help with the 2002 elections. I immediately began to get letters requesting these huge amounts, and now when they call they start way higher. It really makes me mad.
I try to do my part, but all the letters, pleas, etc. just anger me. I want them to win, I'll donate what I can, when I can, I just wish they'd leave me alone and trust that I won't forget them.