Why do the Republicans have the celebrity candidates?

Until recently, American politics operated on a simple premise: Aspiring politicians must suck up to party bosses, run for local office, earn supporters, master policy details and only then earn a shot at higher office. That model has collapsed. Today’s rising stars take a different escalator — television, social media, podcasts, activism, entertainment or the internet — that goes straight to the top. Their chief currency is not institutional support but the attention economy. Which helps explain why Los Angeles now finds itself facing the possibility that Spencer Pratt could make a mayoral runoff. Pratt, if you’ve been living under...