While a majority of the American public still favors embryonic stem cell research, surveys by the Pew Forum on Religion & Public Life and the Pew Research Center for the People & the Press show that the size of this majority has declined somewhat in recent years. Indeed, after showing consistent increases in the early part of the decade, support for stem cell research fell from a peak of 57% in July 2005 to 51% in August 2007, when the latest poll was conducted. Roughly one-third of the public (35%) opposes embryonic stem cell research, saying that protecting the potential life of embryos is more important than conducting the research, while more than one-in-ten (14%) do not express an opinion on the issue.
Polls consistently show that the issue of stem cell research clearly divides Americans along political lines. According to the 2007 Pew survey, majorities of Democrats (60%) and political independents (55%) say it is more important to conduct stem cell research that might result in new medical cures than it is to avoid destroying the potential life of human embryos, but only 37% of Republicans agree. Moreover, in the same poll, self-identified liberals (69%) and moderates (61%) are nearly twice as likely as conservatives (35%) to support stem cell research.
Differences among religious groups are also quite large. In the most recent Pew poll, for example, solid majorities of the religiously unaffiliated (68%) and white mainline Protestants (58%) support stem cell research. A solid majority of white, non-Hispanic Catholics (59%) also favor the research; among those who attend Mass at least once a week, however, this level of support drops to 46%.
On the other hand, among white evangelical Protestants, only 31% favor embryonic stem cell research, while 57% oppose it. Opposition to stem cell research rises to 68% for those white evangelical Protestants who attend church at least once a week. Black Protestants remain split over the issue, with 40% favoring it, 40% opposing it and 20% expressing no opinion.
Finally, there is an important link between the public's knowledge about the stem cell debate and support for conducting research. Overall, 45% of Americans say they have heard a lot about the issue, while 43% have heard a little and 12% have heard nothing at all. Among those who say they have heard a lot about the issue, fully 62% support conducting research, compared with just a third (33%) of those who have heard nothing at all.
This report was written by David Masci, Senior Research Fellow, Pew Forum on Religion & Public Life.