In the two years since the Supreme Court overturned Roe v. Wade, women who have been denied abortions, often in tragic circumstances, have become powerful messengers for Democratic candidates up and down the ballot — giving interviews, filming ads and, now, appearing at the Democratic National Convention.

Against a black background on the convention stage in Chicago, Amanda Zurawski and her husband, Josh Zurawski, described how she nearly died after going into premature labor at 18 weeks of pregnancy. Doctors at a hospital in Texas, which has a near-total abortion ban, sent her home, deeming her not sick enough to qualify for an abortion under the law’s exception for life-threatening emergencies.

“Every time I share our story, my heart breaks,” Ms. Zurawski said. “For the baby girl we wanted desperately. For the doctors and nurses who couldn’t help me deliver her safely. For Josh, who feared he would lose me, too. But I was lucky. I lived. So I’ll continue sharing our story, standing with women and families across the country.”

Another woman, Kaitlyn Joshua, recounted being in the middle of a miscarriage and being turned away from two hospitals in Louisiana that feared the potential liability of caring for her.

“I was in pain, bleeding so much my husband feared for my life,” she said. “No woman should experience what I endured, but too many have. They write to me saying, ‘What happened to you happened to me.’ Sometimes they’re miscarrying, scared to tell anyone, even their doctors. Our daughters deserve better.”

And a third woman, Hadley Duvall, who was raped by her stepfather when she was a child, spoke of the pain she felt at the idea that she could have been forced to give birth to a child at the age of 12.

In a line that prompted gasps on the convention floor, Ms. Duvall, looking directly into the television cameras, quoted former President Donald J. Trump’s description of states’ passing abortion bans as a “beautiful thing” and asked, “What is so beautiful about a child having to carry her parent’s child?”

Public support for abortion rights has increased since the Supreme Court ruling in 2022, which was made possible by Mr. Trump’s appointment of three justices, and for which Mr. Trump has taken credit. That increasing support, and the growing salience of abortion rights to voters, helped fuel a stronger-than-expected Democratic performance in the midterm elections, and the Harris campaign is now leaning into the issue heavily.

Much of the messaging over the past two years has focused on cases like those of Ms. Zurawski, Ms. Joshua and Ms. Duvall, who have all previously appeared in ads for Democratic candidates.