Getting confused about what the First Amendment says about public displays of religious imagery has become as much a Christmas tradition as hanging stockings and watching the Grinch steal Christmas.

This year’s focus of holiday head-scratching is Catherine Gordon, a Bangor High School math teacher, who was told that she had to take down her pink Hello Kitty Christmas tree, because it violated school policy against favoring one religion over others.

Principal Paul Butler may have been well-intentioned, but he was wrong, as he realized when he quickly caved as soon as the story broke on Tuesday. The tree in Gordon’s classroom is back up, and although the problem has been resolved, it shows how many people an over-cautious official can offend when he is trying to offend no one.

Christmas may be a religious holiday, but a Christmas tree is not a religious symbol, and does not have to be excluded from public holiday celebrations. The teacher was within her rights to decorate her classroom as she has done for 30 years, and telling her otherwise unnecessarily started a controversy that tears people apart.

First, it makes sense to look at what the Constitution says about freedom of religion. “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof.”

Religious displays by schools and other public entities usually are tripped up by the “establishment” clause, but it’s not an outright ban. Even overtly religious images such as Nativity scenes can be permissible in some circumstances, according to the Supreme Court. But secular Christmas symbols, such as candy canes and elves, do not establish a state religion nor prohibit anyone else from observing their own. And that’s why Gordon’s pink Christmas tree with cartoon decorations should have been allowed to stay up.

There is a secular Christmas as well as the religious one, and in America it is observed by millions of people who belong to every religion, as well as people who have no religion — if only by enjoying a day off work.

And the Christmas tree is part of the secular observance. It comes from medieval Germany, not the ancient Middle East, and its roots are in pagan practices that were incorporated into holiday celebrations in Europe. There is no more reason to take down a Christmas tree than there would be to ban a turkey decoration at Thanksgiving (also a holiday with religious roots.)

Sensitivity around school holiday displays comes from the fact that for many years public schools did go too far and promoted Christianity to students of every faith. There were school-sponsored pageants, with children dressed as Joseph and Mary, and concerts in which children were taught explicitly religious Christmas hymns, such as “Joy to the World” and “Silent Night.”

These displays were an endorsement of a religion, and used public funds to exclude students who were not Christian.

But now public officials are so afraid of breaking the rules that they are willing to err on the side of being ridiculous. That fuels the notion that there is a “war on Christmas” that prevents people from celebrating Christmas in public despite the fact that no holiday in America is more publicly celebrated than the one that falls on Dec. 25.

An artificial pink tree with Hello Kitty decorations does not establish a state religion, and it does not interfere with anyone practicing their own. Brightening up a classroom — especially a math classroom — in the darkest time of year is a benefit that everyone can enjoy.

Principal Butler has come around in time, but he really should have known better.