At the time, the anti-abortion cause was primarily one pressed by Catholics, and it was strongest in Northern states with large Catholic populations.

Evangelicals, dominant in the South, were largely moderate on the issue, generally opposing “on-demand” abortion but open to a variety of exceptions. A 1969 poll by the Baptist Standard found that 90 percent of Texas Baptists thought the state’s abortion laws were too restrictive. W.A. Criswell, a prominent Southern Baptist pastor in Dallas and former president of the Southern Baptist Convention, remarked in reaction to Roe v. Wade, “I have always felt that it was only after a child was born and had a life separate from its mother that it became an individual person.” (By the end of the 1970s, though, Mr. Criswell opposed abortion rights.)

Over the decades, Texans continued to elect senators who favored abortion rights into the early 21st century. But by then, the anti-abortion movement had become a powerful force in evangelical culture.

And the state, once solidly in Democratic hands, shifted to Republican control in the mid-1990s. Since 2003, Republicans have held majorities in both chambers of the state legislature and the governor’s office. It is also covered by a conservative federal appeals court, the Fifth Circuit in Louisiana.

Like many other states across the South and Midwest, Texas has steadily chipped away at legal and practical access to abortion for decades, including requiring pregnant women to undergo a sonogram — by the same doctor who will perform the abortion — at least 24 hours before the procedure. Other measures, such as the Alternatives to Abortion program, have helped fund pregnancy centers like Prestonwood, which was founded three decades ago as a ministry of Prestonwood Baptist Church, a nearby evangelical megachurch.

In contrast, there are about 24 abortion clinics in Texas, down from 40 less than a decade ago, an imbalance to the scores of pregnancy centers like Prestonwood that speaks to the cultural and political success of the anti-abortion movement, even as the state’s largest and bluest cities get larger and more progressive. The number of abortion clinics is sure to drop further, abortion rights advocates said, as many will be forced to close if the new law remains in place.

In an emergency application asking the U.S. Supreme Court to intervene, a coalition of abortion providers warned that the law — which bans abortions at the point when cardiac activity is detected, generally about six weeks, when many women don’t yet know they are pregnant — “would immediately and catastrophically reduce abortion access in Texas.” Clinics raced to see clients until the minute the law went into effect last week.