Polls taken by CBS News and the New York Times vary in question format and, for a host of reasons detailed below*, are too complicated for straightforward comparison. But they’re consistent with the overall trend. In 2012, at an intensity level of 34 percent, intense pro-lifers outnumbered intense pro-choicers by six percentage points. In 1999, at an intensity level of 37 percent, the pro-life advantage was four points. In 2004, at an intensity level of 38 percent, the advantage was zero.
These data are complex and open to many interpretations. Pro/con questions and intensity questions varied from pollster to pollster and sometimes from year to year. But one basic takeaway stands out: When the intensity level stays low, around 20 percent or less, the population of Americans most likely to base their voting decisions on this issue is more pro-life than pro-choice. To cancel out that advantage, pro-choicers have to raise the intensity level. When the percentage of respondents who call abortion critical, very important, or a deal-breaker rises toward 30 percent or more, the balance of power begins to shift.
Think about that when you see pro-lifers winning elections, passing laws, and marching in the cold. They don’t win because they’re a majority. They win because they care enough to fight.
*Details of CBS/NYT surveys: In 1999, CBS/NYT asked, “How important is it to you that the presidential candidate you vote for shares your views on the issue of abortion?” Thirty-seven percent of respondents said it was very important. In the sample as a whole, 34 percent said “abortion should be generally available to those who want it,” while 22 percent said “abortion should not be permitted.” (The poll’s middle option—“abortion should be available but under stricter limits than it is now”—is too ambiguous to assign to either side.) In the high-intensity subsample—those who said it was “very important” that a candidate share their abortion views—the percentage who said abortion shouldn’t be permitted rose 12 points. But the percentage who said abortion should be generally available fell only 4 points. The resulting pro-life advantage—34 to 30 percent—was tighter than in any of the Gallup polls.
In 2004, CBS/NYT asked, “Is it possible that you would ever vote for a candidate who does not share your views on the issue of abortion?” Thirty-eight percent of respondents said no. In the overall sample, 34 percent said abortion should be generally available, while 21 percent said abortion shouldn’t be permitted. In the high-intensity subsample, the percentage who said abortion shouldn’t be permitted rose 13 points. But the percentage who said abortion should be generally available didn’t decline at all. The result was a dead heat among high-intensity respondents.
In 2012, a CBS News poll combined the 2004 intensity question with a different pro/con question: whether abortion should be “permitted in all cases,” “permitted, but subject to greater restrictions than it is now,” “permitted only in cases such as rape, incest or to save the woman's life,” permitted only “to save the woman's life,” or not “permitted at all.” Thirty-four percent of respondents said they couldn’t vote for a candidate who didn’t share their abortion views. In the overall sample, 35 percent said abortion should be permitted in all cases, while 48 percent said it should be prohibited with few or no exceptions. (Again, the “permitted but with greater restrictions” option is too ambiguous to assign to either side.) In the high-intensity subsample, the percentage who said abortion should be prohibited increased by only 4 points. Furthermore, this very slight bump was matched by a 3-point increase in the percentage who said abortion should be permitted in all cases. This is the only time I’ve seen no measurable net decline in pro-choice sentiment, relative to pro-life sentiment, when the pool narrows to high-intensity respondents.
Caveats: Pro/con questions, and sometimes intensity questions, differed among the Pew and CBS/NYT polls, and among polling organizations generally. In the CBS/NYT polls, shifts in support for the “permitted with greater restrictions” option may signify factors I’ve missed. The five restriction scenarios offered in the 2012 CBS/NYT poll, with the rape exception as the middle option, may have skewed this poll to the pro-life side.
This analysis of previously unpublished cross-tabulations would not have been possible without the generous assistance of several polling organizations. Thank you to Jennifer De Pinto of the CBS News Polling Unit, Jocelyn Kiley of the Pew Research Center, Alena Naff of Gallup, April Radocchio and Ralph Hansen of the Quinnipiac University Polling Institute, Jon Cohen of the Washington Post, and Slate intern Zahra Ahmed.