Despite the widespread use of negative campaigns, research has not yet provided unambiguous conclusions about their effects. So far studies, however, have mainly focused on very explicit measures. The main goal of the present work was to explore the effects of different types of negative campaigns on both implicit and explicit attitudes, as well as in relation to two basic dimensions of social perception, namely competence and warmth. Across a series of three studies, we basically showed that not all negative campaigns lead to the same consequences. Specifically, especially personal attacks toward the opposing candidate may backfire at the explicit level. More interestingly, at an implicit level, the reliance on negative messages was associated with more negative spontaneous affective responses toward the source, but also with a spontaneous conformity to such a source. Overall, it appeared that negative messages decreased the perceived warmth of the source while simultaneously increasing the perceived competence. Results are discussed by focusing on the importance of implicit measures in political psychology and on the crucial role of perceived competence.