Anger leads to perceptions of capability. In the three studies that did not involve Clinton, Tiedens asked why the angry leaders were favored. Participants said they saw them as being highly competent. At the same time, participants said those expressing sadness or guilt were viewed as likable and warm, though not chosen for leadership. The question is whether those are the only characteristics that should matter.
Anger can be useful.
Anger is a very concise and powerful way to communicate when things are going wrong. The emotions expressed in response to a negative event can influence people's views about who deserves status and power.