Why the Fringiest Fringe of the G.O.P. Now Has So Much Power Over the Party

For the first time in nearly a century, we have witnessed the stunning spectacle of a Republican Party so fractured it has struggled in multiple rounds of balloting to choose a speaker of the House. This Washington drama reflects larger structural forces that are changing American democracy.

Revolutions in communications and technology have transformed our democracy in more profound ways than just the more familiar issues of misinformation, hate speech and the like. They have enabled individual members of Congress to function, even thrive, as free agents. They have flattened...