Before revision: To forecast political elections , popular pollsters and forecasters gather polls and combine information from them with fundamental data such as historical trends, the national economy, and incumbency.
After revision: Forecasting elections --- a challenging, high-stakes problem --- is the subject of much uncertainty, subjectivity, and media scrutiny. To shed light on this process , popular pollsters and forecasters gather polls and combine information from them with fundamental data such as historical trends, the national economy, and incumbency.