One of the most difficult things to establish about evangelicals is a precise estimate of just how many of them there are in the United States. With so many different evangelical denominations, evangelical constituencies of varying sizes within historically evangelical “mainline” and even non-evangelical denominations (thousands upon thousands of independent churches) there is no single entity that can possibly serve as a representative gatekeeper for the nation’s evangelicals.
For this reason, the best approach to an evangelical head count is a judicious triangulation of various scientific surveys. But, even this is fraught with problems. As the discussion about the intricacies of definition above would indicate, the framing of the definition or wording of survey questions are important variables that can produce varying results. Estimates of the number of evangelicals in the United States, therefore, are just that: estimates.
Since 1976 the Gallup organization has been asking roughly 1,000 adults the question “Would you describe yourself as a ‘born-again’ or evangelical Christian?” In that first survey 34% of the people being surveyed responded “yes.” Over the years, the number has fluctuated dramatically, reaching a low of 33% in 1987 and 1988 during the televangelist scandals, and a high of 47% in 1998.
The Gallup numbers, however, have averaged just under 39% of the population as accepting identification as born-again/evangelical. According to the most recent sampling of this Gallup poll in 2005, numbers varied from quarter to quarter when the question was asked, but usually came in somewhere between the high 30s and low 40s percentage-wise. See here.
However, describing one’s self as “born again” as the definitive label for evangelical believers–or even the term “evangelical” for that matter–is a questionable benchmark for tabulating the evangelical population (in one study, only 75% of Southern Baptists accepted either term). For a variety of reasons, some groups and individuals which one would describe as “in the team picture” simply do not use those words to describe themselves. For instance, several recent studies and surveys by sociologists and political scientists that utilize more complex definitional parameters have estimated the number of evangelicals in the U. S. at about 25-30% of the population, or roughly between 70 and 80 million people.
It should be noted, however, that even these estimates tend to separate out nearly all of the nation’s African American Protestant population (roughly 8-9% of the U. S. population), which is overwhelmingly evangelical in theology and orientation (for example, 61% of blacks–the highest of any racial group, by far–described themselves as “born-again” in the 2001 Gallup poll). When all is said and done, a general estimate of the nation’s evangelical population could safely be said to average somewhere between 30-35% of the population, or about 100 million Americans.