What a silly letter. Most people I know appreciate Christmas, say"Merry Christmas" to people who celebrate it, "Happy Hanukkah" to people who celebrate that holiday or "Happy Holidays" to people they aren't sure about. The vast majority of people I know do not attend church or consider themselves Christians other than perhaps culturally to a greater or lesser degree. 
No one is waging a war on Christmas except in the paranoid imaginations of right-wing Christians. The U.S. is a multicultural society and people are simply keeping up with the changes in society by recognizing that there are many different traditions in this country, not just Christian ones. People of every faith love their god and when they say the Pledge of Allegiance they are most likely thinking of their own conception of god whether it be Allah, God the Father, Nature, etc. Others who do not believe in the existence of god might omit that part of the pledge without consequence.