School is supposed to be where young Americans learn about the Constitution's guarantee of freedom of speech.

It's not where students should be ridiculed for expressing a preference in the presidential election. Children can't vote, but they can let the adults who do know which candidate they like and why.

That could create one of those coveted teachable moments in which students, guided by a capable teacher, get to exchange ideas and learn something valuable without resorting to a dull textbook, website entry, or video.

Unfortunately, that's not what happened to Samantha Pawlucy, a 16-year-old sophomore at Charles Carroll High School, who was ridiculed by her geometry teacher on Sept. 28 for wearing a pink T-shirt expressing support for the Romney-Ryan presidential election ticket.

Pawlucy says her geometry teacher, Lynette Gaymon, said wearing the T-shirt in a "Democratic" school was as absurd as it would be for Gaymon, a black woman, to wear a Ku Klux Klan shirt. The child said the teacher went into the hallway to call other students and an aide into the room to laugh at the shirt.

Gaymon told the girl to leave the classroom, Pawlucy said, adding that she was so humiliated that she hid in the bathroom the next time she was supposed to go to geometry class.

In the heat of a tightly contested presidential race, the story was picked up by news media nationally. Gaymon's aunts later said the teacher, who has made no public statement, had apologized to Pawlucy and that she regretted her actions, which she meant to be a joke. It seems the adult was guilty of acting like a child.

But the story doesn't end there. As so often is the case when politics and race are involved, people have taken sides. Threats of violence are said to have been made against both Gaymon and Pawlucy. Mayor Nutter over the weekend visited both Gaymon and Pawlucy, but wouldn't comment on the conversations.

It's not too late for that teachable moment. Not just at Carroll School in Port Richmond, but at schools all over the city and elsewhere. Use the case of Samantha Pawlucy in civics classes to teach a valuable lesson about the Constitution, and voting, and respect.