Texas state Sen. Wendy Davis begins a filibuster in an effort to kill a bill that would ban abortion after 20 weeks of pregnancy.

Story highlights

NEW: Sen. Wendy Davis said to have digressed

Davis would have had to hold the floor until midnight

"Blind partisanship and personal political ambition" drive the bill, she says

Critics say the law would shut most of the state's abortion clinics

CNN  — 

A Texas state senator tried Tuesday to block an abortion bill by attempting a 13-hour filibuster, but appeared to fall short after 10 hours when the chairman ruled she had gone off topic.

But a member of the Senate then moved that the ruling be appealed, and the status of the ruling was in doubt.

Fort Worth Democrat Wendy Davis, 50, took to the floor of the chamber late Tuesday morning to criticize the bill, which would be among the nation’s most restrictive. Rules called for her to stand, unaided, until midnight (1 a.m. Wednesday ET), for the filibuster to succeed.

At the outset, Davis said she was speaking for families whose “personal relationships with their doctor and their creator” would be violated by the bill.

“These voices have been silenced by a governor who made blind partisanship and personal political ambition the official business of our great state,” she said. “And sadly, he’s being abetted by legislative leaders who either share this blind partisanship or simply do not have the strength to oppose it.”

Davis had a snack and a small amount of water before beginning, her office said. She was not allowed to lean or take a bathroom break.

At about 10 p.m. (11 p.m. ET), Davis talked about the abortion pill, RU-486, and the chairman ruled that her comments were off topic. Earlier in the evening, a fellow senator helped Davis put on a back brace, which angered some lawmakers who said it violated filibuster rules. That view was upheld in a vote, and she was given a warning.

Before that, she had been ruled off topic.

Davis was allowed three warnings before the Senate was to be allowed to vote on whether she must stop her filibuster.

The sneaker-wearing senator spent much of the time reading testimony and messages from women decrying the bill and recounting stories of the struggles they, their friends or relatives faced in the days before birth control and abortion were legalized.

“Women realize that these bills will not protect their heath,” she said. “They will only reduce their access to abortion providers and limit their ability to make their own family-planning decisions.”

The bill would ban most abortions after 20 weeks of pregnancy and tighten standards on abortion clinics and the doctors who work at them. Critics say it would shut most of the abortion clinics in Texas.

It has passed the state House of Representatives, and Gov. Rick Perry, a former Republican presidential candidate, has said he’ll sign it.

“In Texas, we value all life, and we’ve worked to cultivate a culture that supports the birth of every child,” Perry said. “We have an obligation to protect unborn children, and to hold those who peddle these abortions to standards that would minimize the death, disease and pain they cause.”

While Republicans hold a majority in the Senate, they don’t appear to have the votes to thwart a filibuster.

Abortion rights advocates were rallying behind Davis online, pushing the hashtag #standwithwendy on Twitter.

“Like never before, people in Texas are standing up to demand that politicians respect women’s ability to make our own personal medical decisions, and the whole country is watching,” Cecile Richards, president of the Planned Parenthood Action Fund, said in a statement on the filibuster.

Richards – the daughter of former Texas Gov. Ann Richards – said, “This bill is dangerous and deeply unpopular, and it will hurt a lot of women. We won’t go back, we won’t back down, and we won’t forget when these politicians are on the ballot.”

“Partisanship and ambition are not unusual in a state capitol, but here, in Texas, right now, it has risen to a level of profound irresponsibility and the raw abuse of power,” she said in a statement on her website.

Davis was elected to the Texas Senate in 2008, defeating a longtime Republican incumbent.

Last year, she staged a filibuster to force a special session in an attempt to stop $5 billion in cuts to Texas public schools, according to her website.

Davis, who became a single mother at age 19, went on to graduate with honors from Harvard Law School, it says.

CNN’s Ed Payne and Dave Alsup contributed to this report.