The conventional wisdom about negative political campaigning holds that it works, i.e., it has the consequences its practitioners intend. Many observers also fear that negative campaigning has unintended but detrimental effects on the political system itself. An earlier meta-analytic assessment of the relevant literature found no reliable evidence for these claims, but since then the research literature has more than doubled in size and has greatly improved in quality. We reexamine this literature and find that the major conclusions from the earlier meta-analysis still hold. All told, the research literature does not bear out the idea that negative campaigning is an effective means of winning votes, even though it tends to be more memorable and stimulate knowledge about the campaign. Nor is there any reliable evidence that negative campaigning depresses voter turnout, though it does slightly lower feelings of political efficacy, trust in government, and possibly overall public mood.