This study examined the influence of soft-money-sponsored issue-advocacy advertising in U.S. House and Senate campaigns, comparing its effects against candidate-sponsored positive advertising and contrast advertising on viewers' candidate preferences and on their attitudes that reflect democratic values. The results revealed no main effects for advertising approach on candidate preference. Instead, advertising approach exerted unique impacts based on viewer party affiliation: Advocacy ads influenced only nonpartisans, whereas candidate-sponsored contrast advertising primarily affected Republicans. Viewer exposure to candidate-sponsored advertising, both positive and contrast, elicited greater viewer awareness and interest in campaigns and more knowledge of the candidates and their positions, both in comparison to the control condition and to soft-money-sponsored issue-advocacy ads.