For my european eyes it is astonishing that this data is available so openly even on a street level. Everybody has seen maps of the red/blue states, but this map shows you red/blue quarters and even blocks/streets. Ever wonder which party the weird guy next door prefers? Take a look! As my relatives in the US live in quite unambiguous areas of party preferences, there were not many surprises to me. However it's interesting to see that there are some red/blue sheep living next to them.
It is good thing that any citizen can track any cent of (official

) donations to political parties. Here data privacy laws - and of course vital interests of the involved parties - prevent a true open access to this data.
GR: Same here, I always stay true to the poetic sentence of the great NY band SFA: "I'm not a racist - I just hate everybody! (equally)".