The Amazing Spider-Man #600 by Various (2009)
Perhaps Obama should be a little more cautious in choosing his allies. After all, if he's planning on implementing comprehensive health reform, he might lose a considerable amount of public support if Spider-Man is running around, accusing people of being hippies and destroying the nation's values. And if Spidey's opinions on policy are this easily manipulated, he would not make a great representative for Obama anyway.
Actually looking at the cover for The Amazing Spider-Man #583 makes me think that Spider-Man is not so much a partner of Obama as he is a spy. Hiding in the background and taking photos is not conducive to trust. Plus it seems that all he cares about is fame and having his face on the dollar bill.