Why do famous celebrities overwhelmingly support Democrats?

The Democrats in Washington always talk about putting a big tax burden on the rich which is where most top celebrities would be, yet most celebrities are Democrats working with Obama for America and Al Franken for the Senate. A Republican celebrity (outside NASCAR and the PGA) is a rarity. Obama believes is spreading the wealth, but I have seen none of these Democratic celebrities give up their fortune to help the less fortunate. That seems hypocritical to me.