Final answer:
A pollster or campaign polling expert helps political campaigns understand public opinion through scientifically valid polls. They gather data on public sentiment to optimize campaign strategies, resource allocation, and messaging. Polling data significantly influences campaign decisions and actions.
Step-by-step explanation:
The role of a campaign polling expert or pollster is to conduct polls that help campaigns understand public opinion regarding various political candidates and issues. To ensure that these polls are scientifically valid and reliable, pollsters involve statisticians and methodologists who create random and representative samples. They identify which portions of the population are supporters, opponents, or undecided, and assess the effectiveness of the campaign's strategies and messages.
Pollsters play a critical role by providing campaigns with data that influences where to allocate resources, which issues to focus on, and how best to communicate with potential voters. Campaign polls, unlike media polls, are specifically tailored to measure shifts in public opinion which can often be affected by daily news stories and events.
Exit polls are another function of pollsters that involve interviewing voters on Election Day at selected polling sites, though this methodology faces challenges such as non-responsiveness or dishonesty among respondents. Polls do not only have predictive power but also explanatory power, providing insights into why voters make certain choices.
Polling data also benefits incumbents, such as presidents, by shaping the presentation and rhetoric surrounding their decisions and policies based on public sentiment. Moreover, polls determine campaign strategy by identifying likely supporters, shaping messages, and informing logistical decisions like campaign stops and advertising strategies.