There's a German style Christkindlmarkt in downtown Chicago this time of year. Because it's on public property and somebody set up a Nativity, equal time, or something, requires this.
I'm not sure what's sillier, the invocation of what we now understand as an astronomical event, but what was a religious ritual when there was Sun-worship rather than Son-worship (oh, to New Age nutters, there is still Sun worship, although it's usually summer solstice only), or the obeisance to a Founding Document that people of this ilk interpret narrowly, e.g. a creche in public view is not free exercise, and if I recall my Orwell correctly, you're likely to find sympathy for a narrow reading of the Second Amendment as applying to the militia, not the people, and the Tenth Amendment might as well be a dead letter to these folks. “One sometimes gets the impression that the mere words ‘Socialism’ and ‘Communism’ draw towards them with magnetic force every fruit-juice drinker, nudist, sandal-wearer, sex-maniac, Quaker, ‘Nature Cure’ quack, pacifist, and feminist in England.” Applies to the Organized Atheists as well. Have a nice day.