Is the ground shifting under abortion? Polls, court rulings seem to say so.

Gallup finds increasing support for the pro-choice view on abortion as liberals now match conservatives on social issues for the first time since 1999. Will this impact the 2016 presidential election?

Abortion has always been a political issue – back before the US Supreme Court made it legal (with some restrictions) in the 1973 Roe v. Wade case. And with another presidential election coming up – pitting generally antiabortion Republicans against Democrats who support abortion rights – that’s unlikely to change.

But the ground may be shifting under this key social issue.

Recent court cases have pushed back against state-imposed restrictions on abortion, and polls show that the pro-choice position among Americans now has what Gallup says is a “statistically significant lead.” Another recent Gallup poll shows abortion edging up as an important voting issue.

For the first time since 2008, Gallup reported Friday, half of all Americans identify themselves as "pro-choice" on abortion, surpassing the 44 percent who identify as "pro-life,” a near reversal of the figures from as recently as 2013.

Put another way, according to this poll, 78 percent say abortion should be legal at least under some circumstances – 29 percent say “any” circumstances, 13 percent in “most” circumstances – compared with just 19 percent who hold that abortion should always be illegal.

While public views on abortion continue to fluctuate, Gallup’s Lydia Saad writes, “the broader liberal shift in Americans' ideology of late could mean the recent pro-choice expansion has some staying power.” Earlier this month, Gallup reported that “31 percent of Americans describe their views on social issues as generally liberal, matching the percentage who identify as social conservatives for the first time in Gallup records dating back to 1999.”

In another poll out Friday, Gallup reports that 21 percent of voters – a substantial minority – “say they would only vote for a candidate who shares their views on abortion,” a figure that has been going up over the past seven years. 

“Abortion is an ever-present issue in presidential campaigns – and a year before the 2016 election, more Americans than in the past say they will only vote for a candidate who shares their views on abortion,” writes Gallup’s Rebecca Riffkin. “So far, the candidates' abortion positions mostly echo their respective party lines, with Hillary Clinton and her leading potential rivals for the Democratic nomination all embracing the pro-choice label, while most of the likely Republican candidates (other than George Pataki) either call themselves pro-life or favor various limits on abortion and abortion funding.”

Meanwhile, recent decisions indicate the direction federal courts are taking.

• A Wisconsin law required the state’s four abortion clinics to get admitting privileges at local hospitals. But in March, a federal judge ruled the law unconstitutional, a blow to a major antiabortion strategy.

US District Judge William Conley, who had stayed the law last year as he deliberated its constitutionality, conceded that safety is a legitimate concern when it comes to abortion clinics, but ultimately ruled that the law’s remedy far exceeded any problem since so few abortions involved complications, the Monitor’s Patrik Jonsson reported at the time.

"In particular, the State has failed to meet its burden of demonstrating through credible evidence a link between the admitting privileges requirement and a legitimate health interest,” Judge Conley wrote in a 92-page ruling.

• Last week, the US Court of Appeals for the 8th Circuit blocked an Arkansas law that bans abortion after 12 weeks of pregnancy. 

"By banning abortions after 12 weeks' gestation, the Act prohibits women from making the ultimate decision to terminate a pregnancy at a point before viability,” the court ruled. “Because the State made no attempt to refute the plaintiffs' assertions of fact, the district court's summary judgment order [blocking the ban] must be affirmed."

• Also last week, the 9th Circuit Court of Appeals ruled that Idaho's law prohibiting abortions after 20 or more weeks of pregnancy is "unconstitutional because it categorically bans some abortions before viability." (“Viability” is the point at which a fetus has the potential to live outside the womb, described in Roe v. Wade as “usually placed at about seven months (28 weeks) but may occur earlier, even at 24 weeks.”)

In addition to ruling on the 20-week time period, the court said Idaho's requirement that all second-trimester abortions take place in a hospital is also unconstitutional, "because it places an undue burden on a woman's ability to obtain an abortion,” NPR reported.