Michael Gerson: Emptiness at campaign's end

Silver's prediction is not an innovation; it is trend taken to its absurd extreme. He is doing little more than weighting and aggregating state polls and combining them with various historical assumptions to project a future outcome with exaggerated, attention-grabbing exactitude. His work is better summarized as an 86.3 percent confidence that the state polls are correct.

The statistical analysts of politics have all their bases covered. If the state polls are correct, the aggregator gets credit for his insight in trusting them. If the assumptions contained in those polls — on the partisan composition of the electorate or the behavior of independents — are wrong, it is the failure of pollsters, not of statisticians such as Silver. Note to recent college graduates: Strongly consider a profession in which one is right, by definition, 100 percent of the time. It beats poker.

The main problem with this approach to politics is not that it is pseudo scientific but that it is trivial. An election is not a mathematical equation; it is a nation making a decision. People are weighing the priorities of their society and the quality of their leaders. Those views, at any given moment, can be roughly measured. But spreadsheets don't add up to a political community. In a democracy, the convictions of the public ultimately depend on persuasion, which resists quantification.

Put another way: The most interesting and important thing about politics is not the measurement of opinion but the formation of opinion. Public opinion is the product — the outcome — of politics; it is not the substance of politics. If political punditry has any value in a democracy, it is in clarifying large policy issues and ethical debates, not in “scientific” assessments of public views.

The current mania for measurement is a pale reflection of modern political science. Crack open most political science journals and you'll find a profusion of numbers and formulas more suited to the study of physics.