McKINNEY - Public school officials in one of the nation's fastest-growing cities are being accused of violating the separation of church and state.

The controversy has been simmering in this once-tiny cotton-farming community, about 30 miles north of Dallas, since last summer when Rick McDaniel, superintendent of the McKinney Independent School District, prayed at a pulpit adorned with a Christian cross - during a mandatory school employee meeting at a church.

Last month, under pressure from concerned parents, the 24,500-student school district decided to end a decade-plus practice of conducting high school commencement ceremonies at the same church, Prestonwood Baptist, a Southern Baptist megachurch in nearby Plano.

The change outraged Prestonwood Pastor Jack Graham, one of President Trump's evangelical advisers and a former president of the Southern Baptist Convention.

"It appears religious freedom is under attack at the McKinney Public Schools," Graham said in a Twitter post. "It was our refusal to remove the cross from view that created this cowardly decision."

In a follow-up post, Graham added, "Just wondering on what planet a church, synagogue or mosque would be expected to cover its religious symbols to host a public school graduation."

And in another tweet, the pastor alleged that school administrators had "yielded to the pressure of atheist groups and their supporters."

McDaniel's prayer drew the ire of the Wisconsin-based Freedom From Religion Foundation, which demanded that the school "temporarily cover iconography" to keep graduation ceremonies secular.

Its co-president, Annie Laurie Gaylor, said in a statement after the school district's decision: "We are pleased that the school has moved its graduation to a secular location rather than attempt to modify a house of worship into a place that appears secular. The district's decision to change its tradition to protect its students' rights of conscience is anything but cowardly."

Across the nation, church-state clashes like the one in McKinney "are happening more and more," said Charles Haynes, founding director of the Newseum Institute's Religious Freedom Center in Washington, D.C.

"As we grow more religiously diverse in the United States and people are more visible from various religious groups that have long been here but have not been visible, we are being called in these communities to live up to the First Amendment for the first time in many cases," said Haynes, co-author of "Finding Common Ground: A Guide to Religious Liberty in Public Schools."

Haynes said that if a cross or crosses were visible during a public graduation ceremony, that wouldn't necessarily be wrong or unconstitutional. But the church can't require a cross to be visible, nor require students to listen to a pastor.

"Religious freedom isn't a local church putting conditions on a public school using its facility and making sure its cross is visible," Haynes said. "That's the opposite of religious freedom, and that's exactly what the First Amendment is intended to prohibit."

School district spokesman Cody Cunningham said in a statement that there were "a variety of reasons including proximity, availability, attendance capacity and convenience" for moving the graduation events to the secular Allen Event Center in a neighboring suburb.

"In addition to proximity, McKinney ISD acknowledges the fact that parents and community members have expressed opposing views on the appropriateness of holding graduations in a religious facility," Cunningham said. "More recently, the public debate over the venue intensified to a level that would likely have caused a distraction at the commencement ceremonies.

"While community members are entitled to their own opinions on the issue," he added, "graduation is not an event to be used as a platform for religious or ideological debates, but rather a time to celebrate and honor students."

Just since 2000, McKinney has more than tripled in size, hitting an estimated population of nearly 180,000. Last year, it ranked as the third-fastest growing city in America, according to the U.S. Census Bureau.

Seven years ago, in search of a community friendly to his Christian values, James Blanchet moved his family from Southern California to McKinney. When a cashier at Target told him to "Have a blessed day," he felt like he had found it.

Blanchet said Christianity seems to be under increasing attack in some quarters.

But he has no problem with moving McKinney's commencement ceremonies to a secular location.

"If they wanted to hold the graduation at a non-Christian place of worship, I wouldn't feel comfortable with that," he said.