The statistics presented in these figures are noteworthy, but they deal with self-identifiers only-a rather loose association for many people, who are merely nominal members of these religious groups. These respondents probably have undergone religious initiations, such as baptism, and may seek lifecycle events, such as marriage or burial, within these churches and faiths, but they are not regular worshippers and therefore not under the direct and continuous influence of their teachings. To gauge properly the direct influence of religion on contemporary American politics, we must approach the question from another angle.

Closely akin to religions group identification in the minds of most people is membership in or affiliation with a place of worship. Indeed, in his classic definition of religion, the nineteenth-century sociologist Emile Durkheim characterized religions as systems of belief that unite groups of adherents into common modes of worship, which in turn are shared activities that help to organize adherents into churches-or synagogues, temples, mosques, or whatever else a group might chose to call the place in which kindred spirits come together to celebrate, worship, and recognize the commonality of their beliefs.

Whereas some 80 percent of respondents in the ARIS 2001 survey identified themselves with one religious grouping or another, only 54 percent reported residing in a household where either they themselves or someone else said they belonged to a church, temple, synagogue, mosque, or other place of worship. Since the ARIS religious membership question was addressed to the household rather than to the individual respondent, we should expect some discrepancies on this statistic. They do not, however, account for the entire difference between identification and affiliation for the various religious groups.

As Figure 4 shows, the general trend in ARIS 2001 was for the Protestant tradition groups to have the highest membership ratios and the non-Christians the lowest proportions of members to identifiers. For example, 68 percent of those identifying themselves as Pentecostal/Charismatic/Holiness reported church membership, while only 34 percent of those who described themselves as following Eastern Religions (such as Buddhist or Hindu) reported an institutional membership. Though very similar in numbers of self-identifiers, the Mormons exhibited the highest church membership-75 percent-while only 50 percent of adults who identified their religion as Jewish reported temple or synagogue membership.