And, of course, many candidates tend to gear their proposals toward poll outcomes. However, those outcomes are more often based on general questions that skim the surface of the issue. Also consider how long the poll was conducted. Overnight polls are error-prone because of difficulty culling a truly random sample of respondents and the likelihood of bias due to immediate reactions to media coverage. Characteristics of respondents.
Likely voters tend to have voted in the past two elections and to be more informed.
In the 1980s, about 35 percent of those called refused to answer. This is another reason why pollsters should take more time to obtain accurate results. Word selection, biased lead-in questions and response choices all can skew results. Poll questions on abortion can elicit different responses based on wording. Follow-up questions about the details of a policy position yield a clearer picture of public opinion.