You might have heard about Whitefield Academy, the private Christian school in Louisville, Kentucky, that expelled Kayla Kenney, a 15-year-old student, for posting on social media a photo of herself with a rainbow cake. On the surface, it looked ridiculous: this priggish Christian school kicking a teenager out for merely having a rainbow cake for her birthday. The story has gone viral in the national media. The Washington Post, for example, reported: [Kayla’s mother Kimberly] Alford said she is aware that the rainbow-striped flag is a symbol of the LGBTQ community, but emphasized that her daughter’s matching rainbow cake and sweater were simply a coincidental aesthetic and not intended to mean anything more. The expulsion was first covered this week by local news outlets, including the Courier-Journal. “Rainbows don’t mean you’re a certain gender or certain sex or sexuality,” Alford told The Washington Post, adding that she provided the school a receipt from the bakery l...