A frame of June Ayers and clinic volunteers from Dawn Porter’s documentary “Trapped.” Credit: Chris Hilleke)

Documentary filmmaker Dawn Porter was in Jackson, Miss., in 2013 when she read a newspaper article about how the entire Magnolia State was down to one abortion clinic because of a series of restrictions passed by the legislature.

She was shocked. But she found out it was becoming more and more common across the country, because of a series of state regulations that were making it more difficult for such clinics to stay open.

That led her to one state after another, resulting in the new documentary, “Trapped,” which premiered Friday night at the South by Southwest Film Festival.

Most of the footage was shot in Texas and Alabama, where state-passed regulations have whittled away at the ability of clinics to stay open. The constitutionality of those regulations in Texas is expected to ruled on this summer by the Supreme Court. And “Trapped” is scheduled to screen on PBS’s Independent Lens in early June, presumably before the court makes its decision.

It’s also scheduled to open in theaters in major cities, as well.

Former Texas Sen. Wendy Davis, who led an ultimately unsuccessful battle against the regulations, appeared with the director Friday night.

Porter points out in her documentary that the movement against the clinics is well-coordinated, and that legislators in various Southern states have thrown up various regulations to see what sticks. And that has led to a game plan across the South to set up regulations that will essentially lead to the closure of women’s health clinics.

It’s an interesting analysis, and it’s similar to another documentary at SXSW, “Starving the Beast,” which looks at the conservative game plan to cut back funding for state-supported research universities like UT, North Carolina and Wisconsin.

“Trapped” screens again at 3:45 p.m. today (Saturday) at the Alamo South and at 3:30 p.m. next Friday, March 18, at the Alamo South.