Abstract The idea that manipulation relies more heavily on implicit than on explicit communication has been the plank of several earlier and recent debates on argumentation and speaker roles in interactions. The present contribution will inquire into the selective nature of the use of implicit communication in political discourse; notably, analyzing the distribution of presuppositions and implicatures in two political debates, it will be argued that the use of these two implicit communicative devices – and, particularly, that of presupposition – is likely to correlate with the expression of disagreement, notably through aggressive and blasting contents, more often than with other content types. This tendency will be accounted for by considering the evidential meaning presuppositions and implicatures add to an utterance, which contributes to modulating both speaker’s commitment to truth and source identification on the part of the receiver. Data also show that, when face-threatening contents are exchanged, presuppositions epitomize by far the most preferred strategy in both debates.