IT'S ILLOGICAL. It's "irrational." It's dangerous, literally and figuratively.

And it's not about abortion, really.

Yes, last week's U.S. Supreme Court ruling outlawed only so-called "partial-birth abortion."

So what? you may be thinking.

It's a brutal procedure that's infrequently used. Polls show a majority of Americans support the ban.

Other than feminist liberals like myself who decry any abortion restrictions, who cares?

If you're a woman, you should.

Because it's not about abortion. It's about your health - and the court's willingness to put it at risk to serve its ideology.

The court ruled that a doctor can't perform the procedure to save your health, only to save your life - as if there's always a definitive distinction.

The lack of a health exception is a stunning departure from every other Supreme Court abortion ruling since Roe was handed down 34 years ago.

Not to mention that the procedure, medically known as intact dilation and evacuation, was designed to make second-trimester abortions safer, according to Peg Johnston, a past president of the National Coalition of Abortion Providers.

It requires far less poking of medical instruments into the womb at a time when the uterine walls are thin and more subject to being punctured, she said.

So how did the court justify such a dramatic departure from precedent?

Justice Anthony Kennedy cited the state's interest in "preserving and promoting fetal life" as its rationale.

Which is absurd. Because it does no such thing.

As Justice Ruth Bader Ginsberg noted in her scathing dissent, the ruling outlaws only a method of abortion: one in which the fetus is partially delivered and then terminated.

It's still OK to deliver an intact fetus, after it's been terminated by an injection a day or two before.

It's still OK to dismember the fetus in the womb - a procedure arguably as gruesome as so-called partial-birth abortion.

"The law saves not a single fetus from destruction," Ginsberg noted.

"In sum, the notion that the Partial-Birth Abortion Ban Act furthers any legitimate governmental interest is, quite simply, irrational."

All it does is set the stage for the eventual dismantling of Roe v. Wade.

Which, in a perverted way, is the good news.

Because people who've been complacent about reproductive rights are beginning to understand what's at stake with this new court.

"No one thought that Roe was seriously in jeopardy and weren't heeding our warnings about [Justice Samuel] Alito and [Chief Justice John] Roberts," said Aubrey Montgomery, of NARAL Pro Choice Pennsylvania.

"I'd say that now they recognize we were not hyping it up for nothing."

NARAL (formerly the National Abortion Rights Action League) and Planned Parenthood of Southeastern Pennsylvania are urging members to contact their representatives in Congress to support the Freedom of Choice Act, introduced last week, which would codify Roe's protections into law.

And Planned Parenthood has scheduled a Day of Action today, including a protest rally at the Clothespin at 15th and Market from noon to 1 p.m.

"This represents a significant eradication of women's health," said Dayle Steinberg, of Planned Parenthood.

"How far-reaching it's going to be will unfold in years to come." *

E-mail porterj@phillynews.com or call 215-854-5850. For recent columns: