Recipe Tinkering Makes Polls Unpredictable

When pollsters constantly adjust weighting, sample frames, and likely‑voter rules, the distribution and correlation of polling errors change too, so past error patterns become poor guides for forecasting future errors. That makes it hard for models and commentators to calibrate election probabilities, and it increases the value of explicitly modeling correlated errors rather than treating races as independent. — If polling methodology is a moving target, media narratives and models that ignore correlated, methodology‑driven errors will misstate uncertainty and mislead voters and policymakers.