WASHINGTON, DC - JANUARY 22:  Pro-choice activists hold signs as marchers of the annual March for Life arrive in front of the U.S. Supreme Court January 22, 2014 on Capitol Hill in Washington, DC. Pro-life activists from all around the country gathered in Washington for the event to protest the Roe v. Wade Supreme Court decision in 1973 that helped to legalize abortion in the United States.  (Photo by Alex Wong/Getty Images)
Alex Wong/Getty Images/FILE
WASHINGTON, DC - JANUARY 22: Pro-choice activists hold signs as marchers of the annual March for Life arrive in front of the U.S. Supreme Court January 22, 2014 on Capitol Hill in Washington, DC. Pro-life activists from all around the country gathered in Washington for the event to protest the Roe v. Wade Supreme Court decision in 1973 that helped to legalize abortion in the United States. (Photo by Alex Wong/Getty Images)
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Editor’s Note: Editor’s note: This story was originally published on May 10, 2019. It has been updated to reflect Tuesday night’s vote in Alabama.

(CNN) —  

Rapid and dramatic moves by states to ban abortion at six weeks of pregnancy, including Tuesday night’s vote in Alabama to pass the most restrictive abortion bill in the country, appear to set up an immediate fight over Roe v. Wade.

But such direct challenges to the 1973 milestone are years from any Supreme Court hearing, and advocates on both sides are more urgently strategizing over the pending cases that would establish the terms for the eventual showdown.

Their target is Chief Justice John Roberts. Last year’s retirement of centrist conservative Justice Anthony Kennedy landed Roberts at the ideological center of the reconstituted court. The 64-year-old George W. Bush nominee has backed laws that restrict access to abortion, but Roberts has also tried to preserve the institutional stature of the court.

That means dueling advocates are homing in on themes of precedent and regard for the court in the public eye. They are focusing on respect for – or rejection of – past decisions involving the right to end a pregnancy and looking to see how far Roberts and his conservative majority are willing to go.

Justices, too, are positioning themselves. Liberal Justice Stephen Breyer cited one of the key opinions that upheld Roe v. Wade – 1992’s Casey v. Planned Parenthood – in a dissent Monday that warned against upending precedent.

“It is far more dangerous to overrule a decision only because five members of a later court come to agree with earlier dissenters on a difficult legal question,” Breyer wrote. “The majority has surrendered to the temptation to overrule (Monday’s case) even though it is a well reasoned decision that has caused no serious practical problems in the four decades since we decided it. Today’s decision can only cause one to wonder which cases the court will overrule next.”

Breyer may have been sending a message to Roberts and his conservative colleagues.

“Everybody is, in some sense, in dialogue with Chief Justice Roberts,” said Travis J. Tu, of the New York-based Center for Reproductive Rights, representing a Louisiana medical clinic in a case before the justices regarding whether abortion providers must have “admitting privileges” at local hospitals.

Beginning with his confirmation hearings in 2005, when he described any reversal of past Supreme Court rulings as “a jolt to the system,” Roberts has touted the value of precedent. At the same time, the Roberts Court has at times overturned long-standing precedent, most notably last session in a ruling that reversed a 1977 decision affecting organized labor and union fees.

The newer bans enacted since President Donald Trump took office so conflict with Roe v. Wade that not one has yet been enforced or upheld. The Supreme Court may be poised one day to reverse Roe by upholding an abortion ban, but the cases on its doorstep still involve an earlier set of laws. What happens in the Louisiana case, therefore, could be first in a series of incremental rulings on a path that, in the end, would determine the fate Roe v. Wade.

Adding to the uncertainty of how the court will act, the schedule for the Louisiana case, June Medical Services v. Gee, points to a possible Supreme Court ruling in the middle of the 2020 presidential campaign. That simple fact might also affect the chief justice, likely loath to issue a disruptive decision that would further thrust the court into the political sphere.

The accelerating politics in statehouses reflects Trump’s opposition to abortion rights and pledge to appoint justices who oppose abortion rights. With the addition of the Georgia law signed last week, five states since Trump took office in 2017 have adopted bans on abortion when a fetal heartbeat could be detected, as early as six weeks.

These measures clash with Supreme Court precedent that forbids an “undue burden” on a woman’s right to end a pregnancy before viability, that is, when a fetus can live outside the mother. Lower court judges have ruled against such “heartbeat” measures in the past, and none is likely to take effect in the near future.

Still, lawyers representing abortion opponents hope to use the pattern to assert that many Americans do not regard Roe as truly settled, despite its nearly half-century status.

“Our society is moving away from acceptance and reliance on abortion,” said Kevin Theriot, a lawyer with the Arizona-based Alliance Defending Freedom, which has been active in anti-abortion litigation nationwide. Referring to cases that may become “building blocks” for a direct attack on Roe, Theriot said, “All that we need is for the court to say things have changed.”

RELATED: What the Supreme Court is doing behind closed doors

Yet, according to Elizabeth Nash of the Guttmacher Institute, as five states passed laws against abortion, four legislatures have adopted measures since 2017 shoring up abortion rights. The Guttmacher Institute, which was founded in 1968 and supports reproductive rights, tracks state abortion-related legislation.

The country’s abortion rate, meanwhile, has been dropping. The US Centers for Disease Control and Prevention reported last November that the number of abortions was at its lowest level in 10 years. For the survey period of 2006-2015, reported abortions fell from 842,855 to 638,169 – down 24%.

While states rush in, the justices go slow

Roe v. Wade and the Casey case affirming it prohibit government from burdening a woman’s choice before viability, which may occur at about 24 weeks of pregnancy. (A full-term pregnancy lasts about 40 weeks.) The justices reinforced the Casey decision in a 2016 case from Texas. The crucial fifth vote was cast by now-retired Kennedy.

As the justices then invalidated a Texas mandate that doctors be affiliated with a nearby hospital through so-called admitting privileges, the court said the regulation provides few, if any, health benefits for women and erects “a substantial obstacle” to women who want abortions, leading to an “undue burden” on their constitutional right.

Kennedy was succeeded by Justice Brett Kavanaugh who as an appeals court judge narrowly interpreted the protections of Roe for abortion rights. In 2017, he dissented when his US appeals court allowed a 17-year-old immigrant woman to end her pregnancy over objections from the Trump administration. Kavanaugh insisted at the time that the DC Circuit majority’s opinion would lead to a new right for “immediate abortion on demand.”

Based on his past record, Kavanaugh would likely align with fellow conservative Justices Clarence Thomas and Samuel Alito and the first Trump appointee Neil Gorsuch. On the other side of the current court, backing abortion rights, are the four liberals, Ruth Bader Ginsburg, Breyer, Sonia Sotomayor and Elena Kagan.

Since Kavanaugh’s arrival, the high court has so far avoided the abortion controversy. Appeals from Indiana and Alabama officials of state regulations invalidated in lower courts have been scheduled for action by the justices for months. But no public orders have been issued. The justices were scheduled on Thursday again to consider the Indiana law, and they could announce the fate of that case later this month.

The Indiana law, signed by then-Gov. Mike Pence, requires fetal remains to be handled as human remains are, with burial or cremation, and prohibits an abortion if a woman is seeking it solely because of the race, sex or disability of the fetus.

RELATED: Ocasio-Cortez labels new Georgia abortion law as a ‘backdoor ban’

01:56 - Source: CNN
'Heartbeat' law sets up possible challenge to Roe v. Wade

Louisiana physician admitting privileges law

Unlike the Indiana and Alabama disputes, the Louisiana case brought by June Medical Services directly tests whether the new Supreme Court would adhere to recent precedent, in the 2016 Texas case known as Whole Woman’s Health v. Hellerstedt.

The Louisiana law, enacted in 2014 and similar to the Texas measure, would require physicians who perform abortions to have admitting privileges at a hospital within 30 miles of where the abortion would be performed.

A US district court judge declared the Louisiana regulation unconstitutional, saying it would reduce the number of physicians available to perform abortions and close clinics, lead to longer waiting times and new health risks. The US Court of Appeals for the 5th Circuit reversed, rejecting principles from the Whole Woman’s Health decision.

Tu and other lawyers representing June Medical Services have asked the justices to summarily reverse that 5th Circuit ruling, arguing that it flatly conflicts with the 2016 decision.

Roberts had dissented from Whole Woman’s Health decision three years ago. But in February he cast a pivotal vote with the four liberal justices to stop the Louisiana law from taking effect while the clinic filed its appeal. (Kavanaugh dissented with the other conservative justices.)

Heartened by that Roberts’ action, Tu in an April petition cited another move by Roberts in which the chief justice shifted his position when it appeared a lower court was flouting an earlier Supreme Court opinion.

In that case, Moore v. Texas, an inmate contended his intellectual disability made him ineligible for the death penalty. Roberts voted against Moore when his appeal was before the justices in 2017. At that time, Kennedy sided with the four liberals to reject Texas’ outdated medical standards for determining a defendant’s intellectual disability, over the dissenting views of Roberts and the other conservatives.