SIOUX FALLS, S.D. — To know what's at stake in the Supreme Confirmation hearings, it's best to travel 1,200 miles west from the paneled Senate room to a small nondescript clinic in a Great Plains state.

It's best to turn from the blue-and-white charts brandished by senators to the parking lot filled with cars from places as far away as Rapid City or even Wyoming. It's best to turn from the buzz about precedents and privacy to the quiet of a waiting room.

Here, late in the afternoon, the clinic is still full. There's a soldier who will make a 700-mile round trip from the western part of the state. There's a teenager slouching beside a tense mother. There's a rancher, a mother of two high-schoolers and pregnant after having an IUD removed.

This is the only clinic in the state, and this is the only day in the week when a woman can get an abortion in South Dakota. Today, they'll be treated by one of four doctors flown in from Minneapolis because it's impossible to recruit locally. Today's doctor is Miriam McCreary, a mother of four and grandmother of nine, who graduated from medical school in 1958. At 70, she still knows "how desperate women are to end their pregnancies."

One clinic, one day, one doctor. This is what it's like in South Dakota right now under Roe v. Wade. It's also like this in North Dakota and Mississippi, and not very different in Arkansas or a dozen other states.

Anti-abortion lobbyists here boast that South Dakota is the legislative laboratory for testing and imposing state restrictions. Last year, five new restrictions passed, including one, now being challenged, to force doctors to recite a state-written speech saying that abortion ends the life of "a whole, separate, unique living human being." This year, the Legislature, which just opened its 35-day session, is being pressed by a state task force to add more mis-informed consent, more delays, more expensive barriers.

It goes without saying that South Dakota is one of seven states with a "trigger law" ready to ban abortion if Roe is overturned. But something else requires saying: It's possible to add so many burdens onto the back of Roe that it collapses without ever being overturned.

Kate Looby, the thoughtful and energetic state director for Planned Parenthood, puts it simply: Even if Roe is saved, "we'll end up living in a country in which women theoretically have legalized, safe abortion. But for the women of South Dakota, that won't mean anything." She has had to imagine moving this last clinic over the state line to Minnesota.

Here, then, is the lens through which to watch the Alito hearings. Back in D.C., supporters create charts that compare Samuel A. Alito Jr. to Sandra Day O'Connor, "Model Justice." If O'Connor was a moderate, they protest smugly, so is Alito.

Indeed, O'Connor's decision in Casey v. Planned Parenthood ruled that states can regulate abortion as long as they don't impose an "undue burden" on the right. In South Dakota, says Looby ruefully, "the Legislature has never met a burden it didn't like." Has Alito?

Twenty years ago, Alito believed that the Constitution doesn't protect abortion rights. He doesn't disavow that. He laid out a strategy on how to eat away at abortion without a frontal assault on Roe. It was a blueprint pro-lifers have followed, one regulation at a time. Later, as a judge, he said the state could order a woman to notify her husband before she could get an abortion. O'Connor strongly disagreed.

That moderate "model justice" Alito would replace also wrote this: "The ability of women to participate equally in the economic and social life of the nation has been facilitated by their ability to control their reproductive lives." Does Alito agree?

More than 30 million women in America have had abortions since Roe. Seventy percent of Americans say Alito shouldn't be confirmed if he would end Roe. In the hearings, even pro-life senators insist, ironically and disingenuously, that Alito has an "open mind."

But the question is not just whether he'll overturn Roe. It's whether he'd let it be crushed. In 10 years, more than 400 state regulations have been added, and more are coming. When do burdens that force women to state-shop for their rights become "undue"?

Today, at the only clinic in South Dakota, the rancher doesn't know much about Alito but believes abortion "shouldn't be up to anyone but the woman." Tomorrow, Dr. McCreary will fly back to Minneapolis. Kate Looby will drive up to Pierre to fight the next set of regulations.

Meanwhile, back in Washington, Samuel Alito Jr. sits before a committee, and stolidly, doggedly, rejects one vastly overdue burden: telling us what he believes.