About four in 10 Americans said they support abortion rights in a new Gallup poll — the lowest figure recorded by the organization since it began asking the question in 1995.
Fully half of Americans, meanwhile, told Gallup they were against abortion rights.
The results come as a rising number of religious groups file suit over the Obama administration's new contraception mandate, which is part of the 2010 healthcare law, arguing some forms of birth control are equal to abortion.
The Gallup poll, released Wednesday, revealed a six-point drop in the number of self-identified "pro-choice" Americans since the question was last posed in July 2011. At that time, respondents were equally split between "pro-choice" and "pro-life," 47 percent to 47.
Gallup noted that the "pro-choice" identification had held a wide lead in the mid-1990s that narrowed gradually until 2009, when the "pro-life" position first caught up.
Wednesday's results and findings in May 2009 represent the two times the "pro-life" identification has been "significantly ahead," according to Gallup.
In the latest figures, a record-low 41 percent of respondents identified as "pro-choice," while 50 percent identified as "pro-life." In May 2009, the split was 42 percent to 51 — a record high for those who oppose abortion rights.
Planned Parenthood Federation of America president Cecile Richards pointed out in a statement that a majority of Americans — 52 percent — believe abortion should be legal under certain circumstances, according to the poll. Another 25 percent said abortions should be legal under any circumstance.
"Abortion is a deeply personal and often complex decision for a woman," Richards said.
"What this poll makes clear is that labels like ‘pro-choice’ and ‘pro-life’ simply don’t reflect the complexity of how most people actually think and feel about abortion."
She also pointed to another Gallup poll released Wednesday that found that 89 percent of U.S. adults, including 82 percent of U.S. Catholics, say birth control is "morally acceptable."
"This poll reiterates birth control is not a moral issue – it is simply basic health care," Richards said.
"The Affordable Care Act’s birth control coverage benefit means that millions more women will have access to affordable birth control, and this important step forward needs to be maintained."
The issue of abortion has figured prominently in the two years since conservative Republicans swept the U.S. House and many state legislatures.
Among the party's goals is ending government funds to family-planning organizations that provide abortions in addition to preventive healthcare services for women. Federal law already bans taxpayer funding for abortion.
Planned Parenthood, for example, has been targeted several times. A case involving a Texas decision to defund its clinics is now making its way through the courts.
The issue will be relevant throughout the election season, and the Gallup results suggest that Republicans who oppose abortion rights could find key swing voters sympathetic to their position.
Among political independents, the "pro-life" position outdoes the "pro-choice" one for only the second time since 2001, according to Wednesday's poll.
The 47-41 percent split favoring the "pro-life" position resulted in part from a 10-point drop in "pro-choice" independents since 2011. Among Democrats, the "pro-choice" position also lost 10 points in that period, from 68 percent to 58.
Marjorie Dannenfelser, president of The Susan B. Anthony List (SBA List), which works to elect anti-abortion-rights candidates, used the poll to blast Planned Parenthood as "the nation’s number one abortion provider."
"Americans are increasingly identifying with the position of protecting human life," Dannenfelser said. "It’s not shocking that we’re seeing stronger pro-life opinions. This trend has been steady since the early '90s."
The poll's margin of error is 4 percent.
Read more from the survey here.
—Updated at 12:20 p.m.