The question whether the “Harry and Louise” campaign ads,sponsored by the Health Insurance Association of America (HIAA) during the 1993–1994 health care reform debate, influenced public opinion has particular relevance today since interest groups are increasingly choosing commercial-style mass media campaigns to sway public opinion about health policy issues. Our study revisits the issue of the Harry and Louise campaign's influence on public opinion, comparing the ad campaign's messages to changes in opinion about health care reform over a twentysix-month period in Oklahoma. Looking at the overall trends just prior to the introduction of the Harry and Louise campaign, public opinion was going in the “wrong”direction, from the HIAA perspective. Moreover, public opinion continued in the wrong direction until the mid-point of the campaign. However, in either the turning point of the campaign in terms of message content and tone or in the lag period following it, public opinion reversed on each health reform issue and returned to precampaign levels. It appears from these findings that the campaign captured public opinion when support for issues that were unfavorable to HIAA members was increasing and turned public opinion back to pre-campaign levels. The campaign may result in many more such marriages of political interest groups and commercial advertisers for the purpose of demobilizing public support for health policy initiatives that are unfavorable to special interests.