Elena Kagan’s confirmation hearings this week were the first of the Tea Party era. When Republicans pressed Ms. Kagan on the Constitution’s commerce clause and whether she was a legal progressive, they were speaking not just about academic abstractions, but about the very ideas that animate the rebellious, conservative movement.

The Tea Party is often called “loosely organized,” but the unifying philosophy for groups across the country is a belief that the nation can solve its problems — primarily its economic problems, which is what its supporters care most about — if lawmakers stick to a strict interpretation of the Constitution.

Tea Party groups hand out pocket-size copies of the Constitution like party favors at their rallies and meetings. Many supporters take classes about it on weekends, in the evenings or online, sponsored by groups like As a Mom, a Glenn Beck-inspired “Sisterhood of Mommy Patriots,” or the Campaign for Liberty, which Representative Ron Paul created after his unsuccessful run for president in 2008.

They can recite parts of the Constitution by heart and refer to it, by article and section, in casual conversation. They campaign for candidates who promote themselves as “constitutional conservatives.”