The rally 'round the flag effect (or syndrome) is a concept used in political science and international relations to explain increased short-run popular support of a country's government or political leaders during periods of international crisis or war. Because the effect can reduce criticism of governmental policies, it can be seen as a factor of diversionary foreign policy.
Mueller's definition
Political scientist John Mueller suggested the effect in 1970, in a paper called "Presidential Popularity from Truman to Johnson". He defined it as coming from an event with three qualities:
"Is international" "Involves the United States and particularly the President directly" "Specific, dramatic, and sharply focused"
In addition, Mueller created five categories of rallies. Mueller's five categories are:
Sudden US military intervention (e.g., Korean War, Bay of Pigs Invasion) Major diplomatic actions (e.g., Truman Doctrine) Dramatic technological developments (e.g., Sputnik) US-Soviet summit meetings (e.g., Potsdam Conference) Major military developments in ongoing wars (e.g., Tet Offensive) These categories are considered dated by modern political scientists, as they rely heavily on Cold War events.
Causes and duration
Since Mueller's original theories, two schools of thought have emerged to explain the causes of the effect. The first, "The Patriotism School of Thought" holds that in times of crisis, the American public sees the President as the embodiment of national unity. The second, "The Opinion Leadership School" believes that the rally emerges from a lack of criticism from members of the opposition party, most often in the United States Congress. If opposition party members appear to support the president, the media has no conflict to report, thus it appears to the public that all is well with the performance of the president. The two theories have both been criticized, but it is generally accepted that the Patriotism School of thought is better to explain causes of rallies, while the Opinion Leadership School of thought is better to explain duration of rallies. It is also believed that the lower the presidential approval rating before the crisis, the larger the increase will be in terms of percentage points because it leaves the president more room for improvement. For example, Franklin D. Roosevelt only had a 12pp increase in approval from 72% to 84% following the Attack on Pearl Harbor, whereas George W. Bush had a 39pp increase from 51% to 90% following the September 11 attacks.
Another theory about the cause of the effect is believed to be embedded in the US Constitution. Unlike in other countries, the constitution makes the President both head of government and head of state. Because of this, the president receives a temporary boost in popularity because his Head of State role gives him symbolic importance to the American people. However, as time goes on his duties as Head of Government require partisan decisions that polarize opposition parties and diminish popularity. This theory falls in line more with the Opinion Leadership School.
Due to the highly statistical nature of presidential polls, University of Alabama political scientist John O'Neal has approached the study of rally 'round the flag using mathematics. O'Neal has postulated that the Opinion Leadership School is the more accurate of the two using mathematical equations. These equations are based on quantified factors such as the number of headlines from The New York Times about the crisis, the presence of bipartisan support or hostility, and prior popularity of the president.
Political Scientist from The University of California Los Angeles, Matthew A. Baum found that the source of a rally 'round the flag effect is from independents and members of the opposition party shifting their support behind the President after the rallying effect. Baum also found that when the country is more divided or in a worse economic state then the rally effect is larger. This is because more people who are against the president before the rallying event switch to support him afterwards. When the country is divided before the rallying event there is a higher potential increase in support for the President after the rallying event.
In a study by Political Scientist Terrence L. Chapman and Dan Reiter, rallies in Presidential approval ratings were found to be bigger when there was U.N. Security Council supported Militarized interstate disputes (MIDs). Having U.N. Security Council support was found to increase the rally effect in presidential approval by 8 to 9 points compared to when there was not U.N. Security Council support.