During the 2004 Presidential campaign, the Kerry/Edwards ticket came in for some criticism of their graphics, especially by comparison with those of Bush/Cheney. You can see some of the Democratic nominees' collateral here; ; the NY Times dissected the tickets' graphics here.
I was struck by this while driving down 580 the other day, when I saw one of those round Obama car magnets out of the corner of my eye. It used the image on this button.
It's a brilliant logo, and most people won't even notice all the ways it's brilliant. First, it embeds the first letter of the candidate's last name, by being circular. Second, the subliminal rising sun in a blue sky is extremely powerful; it's hidden because the sun is the white void in the middle of the O. The colors are those of the American flag. The rippling red and white stripes come directly from the flag, but they suggest the open road, a plowed field, an undulating hill. The sense of motion is palpable.
So: the candidate's name, the US of A, a very American sense of forward movement, and the dawn of a new day, all wrapped up in an extremely attracting graphical package. Compare to the boring McCain/Palin graphics!