Is politics the new religion?

Mandy will always remember Jan. 6, 2021, in a deeply personal way. Because she was there, inside the U.S. Capitol, supporting her president.

The images she saw that day remain sharp: The giant American flag carried by the crowd as they marched from the Ellipse. Singing “The Star-Spangled Banner” on the Capitol steps. And finally, entering the building through open doors and standing peacefully in its cavernous Rotunda.

She’s aware of the videos showing mob violence. But that must have been on the other side of the Capitol, she...