Christmas trees are not Christian. Neither is Santa Claus. The nativity is. It's not like American Christmas is a heavy-handed religious affair. Everyone likes presents and cocoa, right? 
I don't see any harm in Christians putting up displays of their religion on/around Christmas time. Nor do I see any harm in Hindus putting up statues of Shiva (or whatever) for Diwali, or Jews putting up big menorahs. And, in communities that have been traditionally a Christian majority, I don't see any problem with the cities themselves putting up displays, either.
Ya know, not everything that happens around us has to be a lightning rod for feigned moral outrage. Sometimes a candy cane is just a candy cane.

I don't see any harm in Christians putting up displays of their religion on/around Christmas time. Nor do I see any harm in Hindus putting up statues of Shiva (or whatever) for Diwali, or Jews putting up big menorahs. And, in communities that have been traditionally a Christian majority, I don't see any problem with the cities themselves putting up displays, either.
Ya know, not everything that happens around us has to be a lightning rod for feigned moral outrage. Sometimes a candy cane is just a candy cane.