Bruce Wilson at the Huffington Post points out that for centuries the war of Christmas came from the protestant right. He is correct. First the dour Scots and then the humorless English puritans outlawed Christmas outright. As the name "Christ Mass" suggests, they found the holiday to be too Catholic with some pagan traditions thrown in.
The ban was not particularly successful in England and was repealed in the 1660. Still, the holiday became less and less important until Dickens revived it with a series of Christmas-themed books (A Christmas Carol was the first and most popular). In America the holiday was looked down on by sober authorities since it was mainly celebrated in the 18th century by wassailing. This consisted of going door to door asking for wassail (spiced beer) - sort of an adult trick or treat. The holiday was reinvented by Washington Irving and others as the event we think of.
While there are people on the far religious right who still object to Christmas, these are not the people who refer to "Winter Holiday Trees". In fact the Puritans had a lot in common with today's left. Where the typical Church of England member had a general live and let live attitude, the Puritans were all for making everyone live like Puritans. Some examples:
The Puritans outlawed foods such as mince meat (associated with Christmas). They were against gluttony and drunkenness.
The neo-Puritans are against foods such as trans-fat and fast food. They worry about an obesity crisis.
The Puritans outlawed plays (all plays) as being immoral.
The neo-Puritans want to outlaw talk radio.
The Puritans were strong believers in censorship.
The neo-Puritans have passed speech codes and hate-speech legislation.
The Puritans were against outward displays of wealth as being too worldly. They outlawed the fashionable slashes in clothing.
The neo-Puritans are against large houses (McMansions), large cars, and other signs of wealth.
The Puritans burnt people for blasphemy.
The neo-Puritans have proposed prosecuting global warming deniers for crimes against humanity.
All of this sounds a bit silly until you remember that today's New England liberals are the decedents of the Puritans. That old urge to repress is still there, it just morphed around a bit.