This case study approaches the Facebook discourse of Romania's President Klaus Iohannis in posts during the last year before his second election as President. The excerpts are analyzed in the framework of the pragma-dialectical approach to argumentation and of the speech act theory. The main hypothesis of the study is that the speaker adopts the engaged argumentative style, as opposed to the detached argumentative style. The notion of argumentative style has been recently developed in pragma-dialectics. The study identifies and describes the contribution of expressive, commissive and directive speech acts to strategically maneuvering between maintaining reasonableness and pursuing effectiveness in the resolution of a virtual difference of opinion. The utterances corresponding to the mentioned illocutionary forces are analyzed as instrumental in achieving the argumentative move of advancing an argument at the argumentation stage of the critical discussion model. The use of each particular illocutionary force allows the speaker to express directly explicitly or implicitly - and indirectly: a) his psychological state in accordance with that of (part of) the audience, by showing communion; b) involvement and will of participation in the public life either in traditional events and on felicitous occasions, to value them as premises of forthcoming actions, or to condemn negative attitudes, actions, and behaviors, mainly attributed to his political adversaries, by requesting changes of attitude and line of action; c) his constitutional role in events affecting the public life by evaluating, describing them from a personal and institutional perspective in order to change their public representation. In the argumentation stage of a critical discussion an expressive, a commissive or a directive utterance may be used to achieve the argumentative move of advancing an argument, mainly by using a symptomatic or a causal argumentative scheme. These appear to be particularly fit to the speaker's purpose of reinforcing his status as a president or as a candidate, while articulating at least in part an engaged argumentative style. If the contribution of the expressives to the design of the engaged argumentative style may be disputable, the commissive and the directive speech acts appear as indicators of the style, since they involve strong communion or strong adversity with the addressee of the performative.