Just when I thought the Christmas wars couldn’t get more ridiculous or hostile, along comes the uproar over dueling holiday displays in the rotunda of Washington’s state Capitol.

First a holiday tree, then a menorah, followed by a crèche — and now a “winter solstice” placard declaring all of the above to be hokum.

The red-and-green solstice sign, placed by the Freedom From Religion Foundation, describes religion as “myth and superstition that hardens hearts and enslaves minds.” Happy holidays to you, too.

The in-your-face display proved too much for the hundreds of Washingtonians who rallied to protest the state’s decision to give the anti-religion group space alongside the Nativity. After TV commentator Bill O’Reilly, the self-appointed defender of all things Christmas, weighed in, the brouhaha went national.

O’Reilly is outraged — outraged! He calls Washington Gov. Christine Gregoire a “weak and confused leader” who supports “political correctness gone wild.”

But truth be told, Bill, the governor has no choice under the First Amendment. Of course, the state of Washington could have kept all displays out of the rotunda. Or the state might have been able to put up some official holiday display in the Capitol — as long as the overall message wasn’t an endorsement of religion. But that’s not what happened.

Instead, some years ago the state allowed a business group to put up the “holiday tree” as part of a charity drive. Then in 2006, a rabbi asked to put up a menorah, followed by a Christian group demanding the right to put up a crèche. Rather than go to court, state officials granted space to all three.

Hence the current December dilemma: If the state opens up government space to one private group to proclaim its message, it can’t turn around and prohibit others.

For its part, the Freedom From Religion Foundation, which describes itself as an association of freethinkers (atheists and agnostics), claims it doesn’t want any holiday displays in state capitols.

“But if the state is going to permit a nativity display and create a public forum,” says a spokesman for the group, “then we want to be sure that the views of the 16% of the U.S. population who is not religious are also represented.”

Now other enterprising citizens want in on the holiday fun. One fellow has requested space for a “Festivus” pole, celebrating a fictional holiday created on the sitcom “Seinfeld.” Someone else wants a display honoring the Flying Spaghetti Monster.

Most bizarre of all, Fred Phelps and members of his Westboro Baptist Church of Topeka, Kan. — the anti-gay group infamous for protesting at military funerals — wants to erect a sign with a ditty called “Santa Claus Will Take You to Hell” (sung to the tune of “Santa Claus is Coming to Town”). Only in America.

Last week, overwhelmed state officials finally declared a “moratorium” on any new displays until they can review their policy. Good luck with that in court.

Lest you think all of this silliness is a kooky West Coast phenomenon: After a private group put up a crèche in the Illinois state Capitol this month, the freethinkers followed with their aforementioned winter-solstice sign. Conflict is sure to follow in Illinois and in other states foolhardy enough to open up their capitols’ rotundas.

If culture warriors have their way, competing holiday displays are likely to proliferate. A nationwide movement to erect Nativity scenes on government property is gaining steam — and the freethinkers, Fred Phelps and the spaghetti monster are sure to follow close behind.

I’ll confess it’s hard for me to understand why some religious groups insist on using government property to proclaim their messages, especially when crèches are omnipresent in front of homes, churches and other private property. And I can’t grasp why freethinkers think they advance their cause by denigrating religious faith.

But under the First Amendment, when government space is open to one, it is open to all. Like it or not, the days of a religious monopoly in government settings are numbered.

Thomas Jefferson and James Madison, you may recall, attempted to end the monopoly more than 200 years ago by disestablishing religion in Virginia and then pushing for “no establishment” in the Bill of Rights.

But despite legal disestablishment, the religious-freedom playing field has been far from level in America. That explains the anger of many non-believers who feel that government often treats them as second-class citizens by privileging religion.

The free-for-all in Washington may look like a circus. But it’s also a healthy reminder that religious freedom isn’t only for the religious — nor is free speech just for the polite.

Charles C. Haynes is senior scholar at the First Amendment Center, 555 Pennsylvania Ave., N.W., Washington, D.C. 20001. Web: firstamendmentcenter.org. E-mail: chaynes@freedomforum.org.