Since Mueller, 1973 (War, Presidents, and Public Opinion, John Wiley, New York), the study of Presidential popularity routinely designates certain historical events as “rallying” events, especially the onset of foreign conﬂicts. Subsequent scholarship explores the effect of additional signiﬁcant historical events (such as scandals or bad economic conditions) upon the President’s stock of approval. This paper argues that prior research has misconceptualized “rallies”, which refer to stable increases in approval of the president’s performance, not just a short-lived spike. Volatility is an important but mostly neglected aspect of presidential approval. This paper shows how the systematic causes of volatility can be examined. Volatility
increases across administrations and over time, primarily as a consequence of weakening partisan attachments. Volatility decreases during elections and after honeymoons, and presidentially relevant events vary in their effects on the mean level as well as on volatility. The results have signiﬁcant implications for the support of rational political actors in the legislature and for evidence of the rationality of public opinion.