Joint forecasts reshape campaign strategy

Forecast models that simulate House, Senate, and gubernatorial contests jointly (rather than independently) produce conditional probabilities — e.g., the odds Republicans keep the Senate while losing the House. Those joint probabilities change how campaigns, donors, and media prioritize states, districts, and messaging because tradeoffs (resource allocation, narrative framing) can be evaluated against correlated outcomes. — Makes explicit that a modelling choice (joint vs separate forecasting) changes incentives for political actors and the narratives voters see, so methodology is itself a political lever.