The PollyIssues model predicts the election outcome based on information about how voters expect the candidates to handle the issues. 

This model is based on the assumption that voters select the candidate they expect to perform best in handling the issues. Thus, it is assumed that, for the voter, it is not primarily important how the candidates intend to solve the problems or what policies they promise to pursue. The voters simply want the problems to be solved.

The table below shows information from polls used for forecasting the 2012 U.S. Presidential Election. In particular, the table shows for which issues voters expect Obama to do a better job and for which issues voters favor the Republican party. The complete poll data for this table can be found here.

The percentage of issues for which voters favor Obama is then used asthe single predictor variable in a simple linear regression model. This vote equation was derived from an analysis of the ten elections from 1972 to 2008 with information from nearly 2000 polls. Nine times the model correctly predicted the winner of the popular vote, with one tie. For the most recent three elections from 2000 to 2008, the method outperformed well-established election forecasting methods.   

The chart below shows how the 2012 PollyIssues forecast has developed since January 2011. As can be seen, the model continuously predicted Obama to win the election.