WICHITA, Kan. (AP) — Thousands of anti-abortion activists gathered in Wichita in 1991 for the Summer of Mercy, sparking tumultuous mass protests that led to nearly 2,700 arrests outside local clinics and crowning the anti-abortion group Operation Rescue as the symbol of the movement.

As protesters prepare to return this summer for the 25th anniversary, the broader movement has splintered into disaffected factions and its strategies have evolved along with the shifting political and legal landscape of the abortion debate.

Perhaps most telling is the decision by Operation Rescue and its leader, Troy Newman, to distance itself from the July 16-23 event. Ever since abortion provider Dr. George Tiller was fatally shot in 2009 in his Wichita church, the group has tried to disassociate from more radical activists.

"I am concerned about the sort of zealots that follow them around and the sort of rhetoric," said Newman, who's also a founding member of the Center for Medical Progress, the group whose secretly filmed videos alleged Planned Parenthood sold fetal tissue and set off legislative attempts to cut funding for the largest abortion provider in the U.S.

"We have been able to accomplish a lot more through the political process than we ever were able to get sitting at the doors of an abortion clinic," he said. "I would never speak ill against that tactic, it was certainly something that launched Operation Rescue, and people were passionate about that, but tactics and times change."

While abortion clinic violence remains an ever-present concern, as evidenced by last year's fatal shootings at a Planned Parenthood clinic in Colorado Springs, new strategies in the anti-abortion movement have emerged, most notably the growing numbers of restrictions placed by state legislatures on abortion clinics that culminated this week with an Oklahoma bill that would have effectively banned abortions; it was vetoed. A thwarted move in Congress to strip federal family planning funds from Planned Parenthood has spawned similar efforts in conservative states.

The 2016 return of the Summer of Mercy is being organized by Operation Save America, a Dallas-based Christian fundamentalist group now led by Rusty Thomas, who says he considers the original event a "heaven-sent revival."

"What we started in 1991 we hope to complete in 2016," Thomas said.

Among the featured speakers this year is Matt Trewhella, the founder of the Wisconsin-based Missionaries to the Preborn, which espouses a doctrine for local officials and states to ignore court rulings they consider immoral.

Operation Save America, the successor to Operation Rescue National, has been among the most strident opponents of abortion as well as gay rights and Islam. Thomas said his organization does not advocate killing abortion providers nor support other clinic violence.

Tiller and the Wichita clinic where he had performed late-term abortions had been a target for decades; it was bombed in 1985, and Tiller was shot in both arms in 1993. No abortion services were available in the city after he died until April 2013 when abortion rights group Trust Women opened one in his former facility.

Director Julie Burkhart said the clinic plans to stay open during this year's protests. They have beefed up private security and are working with law enforcement officials. She also plans to display a sign Tiller had in the clinic: "Women need abortions and I am going to do them." It was signed by Tiller.

Burkhart said she'd just gotten involved in abortion care during the 1991 Summer of Mercy, calling it one of those moments that set her on her life's path.

"It was scary, but the most important thing that it did for me it solidified my belief in the fact all people have to be able to determine what is best for themselves and for their families," Burkhart said.

Amid escalating violence at abortion clinics in the 1980s and 1990s, Congress passed the Freedom of Access to Clinic Entrances Act in 1994, aimed at protecting access to abortion services by imposing criminal penalties and civil sanctions. In its wake, the massive blockades like those during 1991 became a thing of past. The 10-year anniversary event organized by Operation Rescue brought a few hundred activists for mostly peaceful protests, only five were arrested.

Newman said no one has contacted him about this year's event. "They know how I feel," he said. The state's largest anti-abortion organization, Kansans for Life, hasn't been approached, either.

"We are not obligated to work with people just because they are pro-life," said Cheryl Sullenger, Operation Rescue's senior vice president. She served about two years in prison for passing along bomb-making materials in a thwarted 1987 conspiracy to bomb a San Diego clinic, but long ago renounced violence and instead embraced a strategy to close clinics by filing complaints with state medical regulators.

But Burkhart, in making her case, recounts something Tiller once wrote about how his clinic would not exist if people didn't want or need its services.

"The community dictates whether we are here or not," she said.

___

Follow Roxana Hegeman on Twitter at: www.twitter.com/rhegeman. Read more of her work at big story.ap.org/content/roxana-hegeman.