DALLAS — After church on a recent Sunday, Emily Mooney smiled as she told her girlfriends about her public act of rebellion. She had slapped a “Beto for Senate’’ sticker on her S.U.V. and driven it to her family’s evangelical church. But then, across the parking lot, deep in conservative, Bible-belt Texas, she spotted a sign of support: the same exact sticker endorsing Beto O’Rourke, the Democrat who is challenging Senator Ted Cruz. “I was like, who is it?” she exclaimed. “Who in this church is doing this?” Listening to Ms. Mooney’s story, the four other evangelical moms standing around...
