When White House press secretary Robert Gibbs described the latest Gallup tracking poll as meaningless last week, he did so knowing that a spirited defense would ensue. Gallup's presidential approval indicator has endured, in one form or another, for over 60 years. It generates more than water cooler conversation; it has become a virtual staple in our weekly -- and now daily -- news diet.
Gibbs mocked the poll, and the president's declining approval ratings, at a White House press conference last Tuesday, saying, "I don't put a lot of stake in -- never have -- in the EKG that is the daily Gallup trend."
In full disclosure, as political scientists we are avid consumers of the Gallup poll. We find their work trustworthy and thoughtfully constructed, and we are friends and professional "networkees" with Gallup employees. That said, Gibbs' remarks may not be merely the product of indignation over his boss' diminishing poll numbers. It is possible, whether he knew it or not, that Gibbs is on to something.
The "meaning" of the weekly presidential approval number is certainly subject to debate. What exactly does "handling his job as president" mean from respondent to respondent? How does the meaning and interpretation of that ambiguous phrase fluctuate from day to day, or week to week? The approval question is a short cut, summary indicator that allows pollsters, pundits and the public to interpret the president's performance as rising or declining, without ever defining what presidential performance is.
But is the presidential approval rating really educative? Does it have some redeeming value, besides that of entertaining us and providing bloggers, pundits and talk-radio hosts with verbal fuel?
The answer is, not necessarily. It turns out that the presidential approval number ebbs and flows with current events, a good deal of which the president does not control. When the economy is booming, presidential approval generally rises. After the attacks on Sept. 11, 2001, President Bush's approval soared, suggesting not only that approval and crisis-based patriotism were highly correlated, but that the meaning of the question had shifted rather suddenly.
President Obama's declining approval numbers look plausibly explainable. Unemployment remains high, and the passage of health care reform, a cornerstone of his campaign, is dubious. The commander in chief has recommended increasing troop levels in Afghanistan, a country many citizens might not even recognize on a globe.
The ratings tell us little about what people think of Obama personally (do we like him), or our trust in him. The numbers do not reflect optimism or pessimism, nor do they suggest that his 2012 re-election chances are in any way perilous. In short, they are a snapshot -- one that is highly correlated with often unforeseen and uncontrollable events that can readily shift the meaning of presidential approval.
Let's not kid ourselves. Since the advent of public opinion surveys, all presidents save Truman have been avid consumers of poll data. President Nixon's advisers even stored polls in a safe. Polls are here, and they remain a valuable guide for gauging the pulse of democracy.
But we should not invest too much in presidential approval. It is just one indicator of the "state of the nation" that Gallup now monitors on a daily and weekly basis. At the same time, statistical literacy does not mean discarding the negative numbers or shooting the polling messenger. Variability is inherent in polling numbers, just as it is with the weather and the rest of life. Would Gibbs so easily dismiss the fluctuations in the daily Dow Jones Industrial Average as meaningless, or only take it seriously when it tanks?
His claim that he does not "pay a lot of attention to the meaninglessness" of the Gallup survey says a lot, but not about how the president interprets polls. Rather, the criticism suggests that Gibbs recognizes the limitations of polls at the same time that he fails to appreciate how daily and weekly variance in survey data are normal and explainable.