Does School's Santa Hat Ban Amount To Religious Discrimination?

What counts as religious discrimination? Today's South Washington County, Minnesota Bulletin carries a story about two local junior high students who claim religious discrimination because the school principal asked them to remove Santa hats they wore to school just before break. Grove Junior High School vice-principal Dale Wolpers says the school has a no-hat policy to prevent disruptive behavior. Students grab each others hats. But Emily Springer and Kristen McVey claim they were discriminated against because on one day earlier in the year two Hmong students were allowed to wear hats associated with the Hmong New Year.