Parents in southwest Minnesota are at odds with a public middle school that is displaying a rainbow flag in its cafeteria, saying the banner for LGBTQ people doesn’t represent their beliefs.

A video recording of a heated public forum Tuesday night at Marshall Middle School shows parents accusing school officials of showing preferential treatment in allowing the gay pride flag but refusing their requests to include Don’t Tread on Me and “straight family” flags in a cultural display.

“What’s next? Curriculum teaching this lifestyle in our classrooms?” asked Mohammed Ahmed.

Tuesday’s meeting was the second about the cafeteria’s rainbow flag. Community members expressed outrage over an account by an eighth grader who said administrators had blocked student attempts to petition for other flags.

During public comment, the Rev. Don LeClere, pastor at the Marshall Evangelical Free Church, said the pride flag is not inclusive.

“There are two sides to this issue,” the Rev. LeClere said. “We are not haters nor are we against individuals in the LGBTQ plus community. But you can also truly love an individual and hold a different viewpoint from them.”

Erick G. Kaardal, an attorney with the Thomas Moore Society who has been retained by local residents, told The Washington Times that Marshall officials need to write rules that prevent the public school from being turned into a “public display of an ideology.”

“Our view is this [rainbow flag] is not curriculum,” Mr. Kaardal said Thursday.

He said school officials were “bullying” students who disagree with an LGBTQ lifestyle.

“Ironically, of course, the rainbow flag is most famous for being involved in protest, but now that flag of protest won’t tolerate counterprotests,” Mr. Kaardal said.

Under the Minnesota Human Rights Act, sexual orientation is a protected class. But Mr. Kaardal says the school’s denial of other flags, such as the Gadsden flag and a banner depicting a heterosexual family, shows that officials are imposing political beliefs on students.

Marshall Public School District Superintendent Scott Monson said in an email that the school has been threatened with a lawsuit.

“Whether that litigation/legal action will come to fruition or not would be speculative on my part,” Mr. Monson wrote.

The battle over representative flags is not new. Earlier this month, a federal judge in Boston ruled that the city did not need to raise a Christian flag at City Hall Plaza, even though LGBTQ flags had been raised.

However, Mr. Kaardal says the dispute over state-sanctioned political expression in Marshall is similar to another case he litigated, in which the Minnesota Supreme Court ultimately struck down a state law prohibiting voters from wearing clothing with political views at polling places. In that case, voters were turned away for wearing T-shirts bearing tea party logos and buttons saying, “Please I.D. Me.”

“We’re not saying that the school can’t pick textbooks [supporting LGBTQ values] or teachers can’t say what they want in this classroom pedagogically,” Mr. Kaardal said. “[But] when they start treating public property as an area of display they can’t have one view represented at all times.”

Still, several parents at Tuesday’s forum stood up to defend the school’s decision to present a rainbow flag.

“I believe that flying the flag of the LGBTQ community will send the clear message to all of our students that all students matter,” said Dawnlynn Greeney, a deacon at Saint James Episcopal Church in Marshall. “As a person, I have no more choice over being Norwegian than over being LGBT-plus.”

Others at the forum echoed the concern that the flag’s removal would further isolate LGBTQ children, who experience higher rates of suicide than non-LGBTQ kids.

Rick Purrington, a Marshall High School history teacher, said that when he visits other schools, he sees pride flag decals in classroom windows as well as LGBTQ pins, buttons and bulletin boards.

“It certainly seems to me that other schools embrace the pride flag,” Mr. Purrington said. “Why? Because they know what the pride flag really stands for a symbol of love, peace, of equality, of acceptance and diversity.”