Detecting campaign effects in imbalanced campaigns the Likud's intraparty referendum over Sharon's disengagement plan

For many years, political communication scholars believed that political campaigns have only minimal effects on the public and subsequently on election results. The main justification for this minimal effects hypothesis was the fact that scholars found it impossible to measure and identify substantial persuasion effects that are the out-come of a campaign. But for more than a decade now, scholars who study political campaigns hypothesize that political campaigns have a strong persuasive effect on the voters. They argue that such persuasive effects could hardly be measured because most major political campaigns are relatively balanced, and therefore have a canceling-out effect. They hypothesize that it would be possible to measure the effects of persuasion in an extremely asymmetric campaign, but they hardly find any such major campaigns in modern times. The campaign over Sharon's disengagement plan in Israel was extremely imbalanced and is therefore an interesting and important example from a theoretical point of view. The analysis provides evidence for persuasion effects of the campaign.