Proudly liberal, unrepentantly wonky, and startlingly young, Ezra Klein came on the scene as a writing fellow for The American Prospect—an incubator for policy-obsessed progressives—at just 22. Klein is passionate about the plumbing of policy, filling his blog with lucid exegeses of health-care reform, environmental bills, and economic legislation in all their tortured details.

Klein is seen as a rising star on the circuit of young Beltway pundits. Among conservatives, his genial tone, cheerful demeanor, and fact-obsessed brand of punditry have won some fans, or at least recognition. His ascent to the first rank of liberal writers, however, has sapped much of that goodwill. Michelle Malkin, a leading blogger on the right, has declared she would rather stand near a “vat of liquid radioactive waste” than share a stage with Klein.