"If they are not willing to give that up, the state's position is going to be that the children are never going to go home. That's going to be state's non-negotiable bottom line," McCown said.
But this is not the first time the sect's practices have been challenged by state authorities, and it was unclear what the long-term impact will be on the polygamous group, which has been raided by authorities in several states four times in the last 75 years.
Though Arizona arrested dozens of men and took hundreds of children into custody in 1953, that raid appeared to have little effect on the group's beliefs or practices, leading some to question whether the results will be any different in Texas.
"I think it will be a repeat of history," said Martha Bradley, a University of Utah professor and author of "Kidnapped From That Land," a study of the now-infamous 1953 raid on the town known then as Short Creek.
Within two years of the raid, all sect members were back in Short Creek.
"Every one of them came back home," said Benjamin Bistline, a former sect member who was 18 at the time.
Texas officials took all of the sect's children into custody last month, claiming the group encourages marriages between underage girls and older men, placing the children at risk of abuse, which sect members deny.
The state believes as many as 31 girls in state custody are under age and either pregnant or are already mothers, a number that has been disputed by the church. The state also claims it has evidence of broken bones and sexual abuse among the boys.
Texas Child Protective Services has said that its ultimate goal is family reunification by April, though if a judge finds the FLDS parents cannot create a safe environment, they may permanently lose custody of their children.
Some lawyers for the children and the sect already have criticized the state's reunification plan, claiming it could require mothers to disavow their religious beliefs and could be read to mean that the mothers would not be allowed to return to their homes on the Yearning for Zion Ranch.
"Every indication from CPS [child protective services] that we have from their actions suggests that would be the case," said Rod Parker, a longtime FLDS lawyer who is acting as a family spokesman.
Patrick Crimmons, a CPS spokesman, called that "rank speculation."
The plan, obtained by ABC News, "doesn't say anything about religious beliefs. It doesn't say anything about polygamy," he said. "All it says is that if they want the kids returned to them, they are going to have to be protected."
The church has cast the case as the latest attack on its religious rights — the continuation of a conflict that has gone on for more than 70 years between the fundamentalist sect and the government.
Last month's raid in Texas is the fourth carried out against the sect by police in different states. The group's largest community, known as Short Creek, straddling the Arizona and Utah borders, was raided in 1935, 1944 and 1953.
The 1953 raid was the most determined by prosecutors. Authorities swept into Short Creek, arrested 36 men and took 86 women and 263 children into state custody and sent them to small towns throughout the state.