The benchmark one of these is generally the first one taken during a political campaign, while a brushfire one of these is taken during a race to size up the competition. The Bradley Effect can occur if someone does not give a candid answer for one of these, and the margin of error measures the difference between a sample and the general population for one of these. Print versions of these once included Harris, Roper, and Gallup, although most are conducted online today. For 10 points, name these indicators of public opinion, usually seen in political campaigns.
a) Exit polls
b) Opinion polls
c) Exit surveys
d) Straw polls