Despite Americans' shifting opinions on a range of moral and ethical issues, abortion foes have been encouraged by numbers showing that opposition to abortion rights appeared to have resisted serious slippage, and was even gaining traction.
But a Gallup poll released Friday shows that may be changing: 50 percent of all Americans now identify as "pro-choice," the first statistically significant lead over the "pro-life" label, which came in at 44 percent, since 2008.
The data suggest this could signal an end to the seesaw battle that has characterized opinions on abortion over the past few years.
"The pro-choice view is not as prevalent among Americans as it was in the mid-1990s, but the momentum for the pro-life position that began when Barack Obama took office has yielded to a pro-choice rebound," Gallup's Lydia Saad wrote in an analysis of the figures, which are from a survey conducted in early May.
"That rebound has essentially restored views to where they were in 2008; today's views are also similar to those found in 2001," she said.
A Vox poll taken earlier this year also found that more Americans identified as "pro-choice" (32 percent) rather than "pro-life" (26 percent).
But it also found that 39 percent -- a plurality -- reject the labels, with 21 percent identifying as neither and 18 percent identifying as both.
Results from a May 26 Gallup survey on Americans' shifting attitudes on a range of hot-button issues showed a uniformly leftward march since 2001, especially on gay and lesbian acceptance.
But those who viewed abortion as "morally acceptable" increased only 3 percent over that period, to 45 percent. An equal number said it was morally wrong.
The newly released data, however, suggest that if Americans continue to have moral qualms about abortion they are increasingly inclined to want to protect the legal right to abortion.
Some 42 percent of respondents said abortions should be legal "under any circumstances" (29 percent) or in "most circumstances" (13 percent) while only 19 percent said that abortions should be illegal "in all circumstances." The poll showed 36 percent said the procedure should be legal "in only a few circumstances."
The shift comes as states have increasingly been restricting access to abortion, with a debate also growing over bills to ban any abortion past the 20-week mark of a pregnancy.
Yet it's not clear that the shift to a "pro-choice" preference will herald a truce in the political battle over abortion that is sure to play a role in the 2016 presidential campaign: Democrats are still most likely to identify as "pro-choice" (68 percent) and Republicans as "pro-life" (31 percent).
Gallup noted in its analysis that it does not define the "pro-choice" and "pro-life" terms for respondents, but says that "their answers to a separate question about the legality of abortion indicate that those favoring the pro-choice label generally support broad abortion rights, while pro-life adherents mostly favor limited or no abortion rights."