As the U.S. Supreme Court considers a Mississippi case directly challenging Roe v. Wade — the 1973 landmark for women’s rights that’s been under fire almost ever since — it’s worth recalling Roe’s troubled, even tormented history that’s brought us to this unfortunate place.

If there’s a consensus prediction on the eventual ruling, it’s that at least five judges will uphold the “moderate” Mississippi law barring abortion after 15 weeks of pregnancy, while striking down the “radical” Texas law, already in effect, with a six-week ban, but also — in a tricky constitutional move — vesting enforcement with private parties.

There’s a slim chance the court will resist overturning Roe, as it did in 1992, with Planned Parenthood v. Casey. Surprising many, Casey upheld Roe’s basic findings, while inviting state restrictions not imposing an “undue burden.”

That language came from Sandra Day O’Connor, a Reagan appointee, joined by a second Reagan appointee, Anthony Kennedy, and by New Hampshire’s David Souter, appointed by George H.W. Bush, to create a 5-4 majority — along with two judges who’d voted for Roe, including its author, Harry Blackmun.

The “undue burden” standard has been frequently tested, but not until this year did four justices, the minimum, entertain a direct challenge to Roe.

Roe’s survival seems unlikely, because Republican presidents have made private opposition a litmus test for appointments. Donald Trump, who made three, said so explicitly.

But the seeds for Roe’s downfall were there from the beginning.

In 1965, the Warren court — history’s high mark for civil liberties ­— struck down a Connecticut law banning contraceptives in Griswold, establishing a “right to privacy” that, while not enumerated in the Constitution, enjoys wide public support.

Like Griswold, Roe was a 7-2 decision, suggesting the court, at least, reached a consensus on abortion. Unfortunately, there’s no indication the broader public was ready for such profound change.

In the 1960s “second wave” feminism had pushed for expanded abortion rights, noting that the original 19^th century state laws banning abortion were generally intended to protect women. Back then, abortion was risky, and often fatal.

With modern surgical techniques, abortion was safe. The original reasoning no longer applied.

Reading Justice Blackmun’s decision now is a melancholy experience, because it’s fraught with unintended consequences, producing an endless public controversy that — in significant measure — modeled the divisive partisanship now afflicting us at every turn.

Even among supporters, Blackmun’s decision was faulted for not just striking down existing state laws, but detailing exactly what state laws should look like: the trimester system, in which abortion is allowed until fetal viability, about 24 weeks.

Blackmun took those provisions not from existing state law, but recommendations by the American Medical Association, later endorsed by the American Bar Association.

The irony is that the AMA effectively abandoned its earlier stance. Hospitals and general surgeons initially provided abortions, but the procedure was driven to private clinics as anti-abortion protests grew.

Four states had enacted laws resembling Roe, including New York under Republican Gov. Nelson Rockefeller. But advocates relied too much on a 1970 referendum in Washington state legalizing abortion.

Two more state referendums appeared in 1972. Michigan soundly rejected abortion liberalization, and North Dakota did so overwhelming. Roe, the following year, arrived at an unpropitious political moment.

Had Roe been less sweeping, based solely on Griswold’s privacy principles, the public consensus might ultimately have arrived at something like Roe. Instead, a permanent opposition movement flourished.

Without this high bar, the legislative process could have continued, with court rulings on acceptable restrictions. Instead, Roe’s sweeping mandate produced two generations of politicians sworn to overturn it.

Consider: Unlike Roe, widespread and growing public support spurred the conservative court’s surprising 2015 Obergefell decision legalizing same-sex marriage. No opposition movement has appeared.

Initially, Roe had prominent bipartisan defenders, including, in Maine, Republican legislators Sherry Huber and Olympia Snowe. John McKernan, Snowe’s future husband, won his 1982 congressional race in part because his Democratic opponent, John Kerry, opposed abortion.

Whatever happens, Maine will remain “pro-choice.” The only time a referendum appeared — the misnamed “partial birth abortion” ban in 1999, describing a rare late-term procedure — it was defeated.

Yet abortion, tragically, is now solidly partisan, with Democratic candidates required to support abortion, with Republicans opposed. The “Casey” of the 1992 case was Gov. Robert Casey, a Pennsylvania’s Democrat; today, that couldn’t happen.

In “blue” states surgical abortion will remain legal, but “red” states will make it difficult or impossible to obtain. Since slavery split the nation, no fundamental constitutional right has depended on the state where one lives.

The court could still pull back, but it’s more likely years of “court packing” will finally produce the intended result.

Douglas Rooks, a Maine editor, commentator and reporter since 1984, is the author of three books. His first, “Statesman: George Mitchell and the Art of the Possible,” is now out in paperback.  He welcomes comment at drooks@tds.net