Transcript for Why the Major Abortion Case in Front of US Supreme Court Matters
Tonight, high stakes in the biggest abortion case in more than two decades. We're inside the very human efforts on both sides of the debate. As many look to make the crucial difference in a legal decision that could impact millions of lives. Here's ABC's Gloria Riviera. Reporter: Separated by just a few feet, but they stand a world apart. Today outside the supreme court, passions inflamed on both sides of America's most enduring culture war. While inside, the most important abortion case being considered in a generation. Improve patient safety. That's what these laws have always been about. They won't promote women's health. They are going to make abortion less safe. Reporter: Arguing that controversial Texas law that regulates abortion clinics as unconstitutional is Stephanie toady. It's her first time at the nation's highest court. But with her, some star power support. I realize the next generation may have less choice than I did. Reporter: Judging Amy and leftovers actress Amy Breneman and 40 other women lent their name to the cause, saying that having an abortion allowed them to have happier, healthier lives. I was 21. It was after my junior year. Reporter: This week, she opened up in this emotional video posted to youtube. I feel so blessed that I was in place that I wasn't "Reshaping it alshamed and I was supported. If you start delving into your family and friends, you're going to find a woman who's terminated a pregnancy. So, therefore, it's in everybody's life. And I draw the line for Whitney. Reporter: Believes restrictions around the country are going too far, she's joined forces with other celebrities in the draw the line campaign. I'm Elizabeth banks, and I draw the line for Rebecca. Reporter: Encouraging women to share their stories about how abortion helped them instead of hurting them. This is not the first campaign of its kind. I had an abortion last year. It was an incredibly positive experience for me because I didn't want to become a mother. Reporter: Last year, Amelia decided to share her story on Facebook. And giving it a hashtag shoutmyabortion, and it went viral. Plenty of people still believe that on some level, if you're a good woman, abortion is a choice that should be accompanied by sadness, shame, or regret. But I have a good heart, and having an abortion made me happy in a totally unqualified way. Reporter: She says she was not surprised by the outpouring because one in three women in this country have had an abortion by the age of 45, according to one study. Within a couple of hours, there were women in and out of my social circle that were just saying, hey, I had an abortion too. I think the shout your abortion campaign is phenomenal. I love it. Reporter: They have taken it personally. Look at you! Martha Plimpton also shared she had a positive experience. For me in particular, because I did have two abortions as a young woman, I feel that my ability to access that kind of medical care made it possible for me to live out my dreams and do what I really wanted to do with my life. Reporter: Among other restrictions, the Texas law requires that abortion clinics are more like surgical centers, and that doctors have admitting privileges at a hospital within 30 miles. You want to be a health care provider, then act like it. That's what we're saying. Reporter: Critics of the law say adhering to the new standards make it impossible for many abortion providers to remain open. Especially in a state the size of Texas. Millions of women in Texas and other states across the region are at risk of losing their constitutional right to access safe abortion care. Reporter: Millions of women. The ripple effect could be huge. Absolutely. We have seen copycat laws in other states in the south. Reporter: And since the law was enacted, half of the abortion clinics in Texas have closed. What kind of personal stories are you hearing? Stories about women having to travel out of state because the waits for an appointment with an abortion provider in Texas have become so long. Reporter: In a new documentary, "Trapped," doctors and nurses at whole women's health, one of the Texas abortion clinics that's challenging, shares stories about how they had to turn away women in need. There's a two to three-week waiting list for a procedure where time is of the essence. I remember getting a call from a patient and said, what if I tell you what I have in my kitchen cabinet, and you tell me what I can do. Reporter: But those on the other side of the issue say that the Texas law and others like it are designed to protect women's health. Anti-abortion activists also submitting briefs to the court, citing 3,000 women who they say suffered grievous psychological injuries after their abortions. A majority of Americans, regardless of whether they say they are pro-life or pro choice on the issue of abortion, agree that abortion should be safe for women. Reporter: Kristen Hawkins is presidents for students for life of America and has recruited thousands to the cause. Today we have come out to show the supreme court justices that this is a pro-life generation. My mission is to abolish abortion. And to make abortion unthinkable and illegal. Reporter: She thinks the stricture regulations on abortion clinics across the nation are just the first step. We're a pro-life generation! Reporter: We were with the young mother last year at one of the largest ever anti-abortion demonstrations. This is what the pro-life movement looks like at its strongest in the United States today. We're at the March for life. And what you see behind me goes on for miles. Today I speak to you pregnant with my fourth child. My first daughter. We are the pro-life generation! Reporter: To some, like 16-year-old Devin, she's a hero. Is this your first March for life? Why did you place your child for adoption? She was born in October of this year. I wanted to have an abortion when I found out I was pregnant with my daughter. And I was given the options that I could do abortion and not tell anyone, or I could leave home. I went to a maternity home and in October I placed my daughter for adoption. And because of her, I'm not ashamed I got pregnant at my age anymore. Reporter: Hawkins regularly conducts what she calls sidewalk counselling outside planned parenthood clinics with student volunteers like Sam from the university of New Mexico. Whenever I sidewalk cancel, it's usually in a back alley on top of a ladder so we can reach the women. Reporter: But the young women on the other side, women who could be her class mates, are just as dedicated. Many feel that the greatest danger is to women, forced to turn to illegal, unsafe alternatives if the Texas law is upheld. Since these laws have taken effect, there's been an increase in attempts at self-induced abortion in Texas. Because they simply can't make the trip that is now required in order to reach an abortion clinic. Reporter: But for now, Stephanie has done what she can. The case rests in the hands of the eight remaining justices. Abortion is a human right! Reporter: But no matter the ruling, we'll likely see this scene play out again and again. Pro women, pro-life! Reporter: This battle isn't ending anytime soon. For "Nightline," I'm Gloria
This transcript has been automatically generated and may not be 100% accurate.