Forecasting the presidential primary vote: Viability, ideology and momentum

The presidential primary vote represents a unique electoral forecasting challenge, with multiple candidates and sequential voting. This study compares the leading primary vote forecast models by re-estimating them for a common set of candidates and nomination campaigns. A new forecast model is estimated to assess the predictive power of candidate ideology, controlling for the effects of variables found to be significant in prior studies. Finally, the study compares the early forecasts, based on data from before the Iowa caucus, with “momentum” models, which are the early models, updated with variables representing the results of the Iowa Caucus and New Hampshire Primary vote, predicting the remaining contested primary vote.