How a Feud Between Two Tea Party Leaders Helped Lay the Groundwork for the Capitol Insurrection

That’s how Amy Kremer greeted the thousands of Trump supporters she had helped gather at the Ellipse in Washington, DC, on January 6 to “stop the steal.” Resplendent onstage in a bold leopard-print shawl, with the White House rising up behind her, the former flight attendant had come a long way since she and another Georgia woman, Jenny Beth Martin, became known as the “founding mothers” of the tea party movement back in 2009.

During the heyday of the grassroots conservative movement that had sprung up to oppose President Barack...