Polling has been controversial, since results vary based on how questions are framed and who asks them.
Based on Gallup polling, the percentages of Americans who believe abortion should be legal under all circumstances, illegal under all circumstances, and legal only under certain circumstances have stayed remarkably stable. The biggest chunk of Americans falls into the last group: 52 percent in 2012, compared with 54 percent in 1975. A quarter of Americans told Gallup last year they believed abortion should be legal in all circumstances, compared with 21 percent in 1975.
Over the past 17 years, however, Gallup polling has shown that fewer Americans identify as favoring abortion rights – declining from 56 percent in 1995 to 41 percent in 2012 (for both years, these responses came after survey-takers had been asked about the legality of abortion).
