According to
Spotlight on Financial Services, the DNC is now offering through Providian a Visa/MasterCard that lets you earn rewards points that you can choose to donate to the DNC or use toward traditional rewards like airline flights. If you make an initial donation to the DNC when you sign up, your points multiply faster. Interesting -- for some, it's perhaps worth a switch.
Doesn't look like it's available yet, but DNC supporters will probably see the pitches soon.