Even before the sex abuse scandal made him one of the most embattled figures in the Catholic church, Archbishop John Nienstedt's tenure was turbulent.

His pricey fight against same-sex marriage had backfired. His unyielding style had riled some priests. And while some parishioners praised his conservative stances, for many he became a polarizing figure among local Catholics.

"He was a warrior bishop waging a cultural war," said Charles Reid, a professor of canon and civil law at the University of St. Thomas.

Unease about Nienstedt's leadership arose before he even moved into the Chancery in St. Paul. As bishop in New Ulm, he became known for his strict adherence to orthodox doctrine — denouncing his predecessor's call for dialogue on opening the priesthood to women; rebuking a priest in St. Peter for worshiping with Lutherans after a 1998 tornado destroyed the town's Catholic church; and urging legislators to support a constitutional amendment defining marriage as between one man and one woman.

Those moves mirrored the attitude of the Vatican under Pope Benedict, who picked Nienstedt as the new archbishop in 2007. But many priests and parishioners in the Archdiocese of St. Paul and Minneapolis, with its long history of being "moderately progressive," greeted his arrival with trepidation, Reid said.

Some watchers believe Nienstedt wanted to bring this Catholic community to a more conservative position on issues including gay marriage. "Nienstedt saw his job, I think, to correct those excesses," Reid said.

He thought himself to be "the referee who was going to keep us in bounds," said Tim Power, a retired archdiocese priest.

Nienstedt emerged as perhaps the most powerful political and financial force behind an effort to pass a constitutional amendment banning same-sex marriage. In 2010, he gave a six-minute introduction to a DVD that was sent to 400,000 Catholics, warning that "at best, so-called same-sex marriage is an untested social experiment, and at worst it poses a dangerous risk with potentially far-reaching consequences." He committed more than $650,000 in church money to the campaign to pass a constitutional amendment banning same-sex marriage in 2012.

The marriage amendment was meant to be Nienstedt's "signature accomplishment," Reid said. "He invested hundreds of thousands of dollars in archdiocesan funds to this. He campaigned heavily for this. And it backfired.

"It backfired so badly that I think it helped change the debate at the national level on same-sex marriage."

In a sense, Nienstedt was in the wrong place at the wrong time, said Power, who served most recently at the Pax Christi Catholic Community in Eden Prairie. Documents show that Nienstedt inherited an organization that had faced allegations of clergy sexual abuse for decades. And at the Vatican, Pope Francis' arrival ushered in a more open, less doctrinaire style.

"Under Benedict, he was an up-and-coming conservative leader — on the fast track," Power said. "All of a sudden, he's in quicksand."

As allegations of sexual abuse mounted and lawsuits piled up, Nienstedt said he never knowingly covered up clergy sexual abuse and, in 2014, argued that the archdiocese was in "a much better place." In July 2014, he declared that he would not resign, arguing that he had "strong pockets of support."

But in September 2014, a dozen Catholic theologians at the University of St. Thomas wrote an open letter to Nienstedt, urging him to begin a process of healing. One of that letter's authors, Massimo Faggioli, said that letter "got no response."

Calls for Nienstedt's resignation swelled when, this month, the Ramsey County attorney's office filed criminal charges against the archdiocese for "failing to protect children" from an abusive priest.

That "very compelling, powerfully written set of criminal charges" will define Nienstedt's tenure, Reid said. "That, by itself, constitutes a legacy."

Before a new archbishop is named, parishioners and priests ought to gather and talk about what the church could become in the coming decades, Power said. "His choice to resign hands us an opening to pull together as a church and start talking to one another," he said, "without his shadow being there."

Jenna Ross • 612-673-7168