“We have a State Capitol that is made up of people, for the most part, who are elected by Anglo communities, suburban and rural, and they are the majority voice in the Capitol, although they aren’t reflective of the majority of the state of Texas,” she said in a previous interview.

On Tuesday night, as she stood in her salmon-colored running shoes on the green carpeted floor of the Senate chamber and spoke about the bill from 11:18 a.m. to about 10 p.m., Republicans monitored virtually her every move and word, waiting to catch her violating Texas’ obscure filibuster rules, which prohibited her from leaning on her desk or straying off topic. At one point they objected when a fellow Democrat tried to help put a back brace around Ms. Davis, who at that point had been standing for about seven hours straight.

“I’m tired, but really happy,” Ms. Davis told reporters in the Senate chamber at 3:20 a.m. Wednesday as she finally made her way out of the building. “I’m pleased to know that a spotlight is shining on Texas, a spotlight is shining on the failure of our current leadership.” She was congratulated by lawmakers and women’s rights advocates. But the celebration was short-lived. Hours later, Gov. Rick Perry announced that a second special session would begin Monday so lawmakers could take up the abortion bill once more. Analysts said the bill would probably pass this time because Democrats in the Republican-controlled Senate would be unable to delay for an entire 30-day session.

As a lawmaker elected to the Senate in 2008, Ms. Davis has shown charisma and guts, and her life story has moved voters. At the age of 14, she worked after-school jobs to help support her mother and three siblings.