MISSION ? The American Civil Liberties Union is urging a Kansas school district to stop telling staff not to wear safety pins on their clothes in a sign of solidarity to the disenfranchised.

The ACLU sent a letter Tuesday to the Shawnee Mission School District about the pins, which have gained popularity in the U.S. following the presidential election of Donald Trump. The pins first began to be worn amid reports of hate crimes in the United Kingdom following that country’s vote in June to leave the European Union. They are intended to show that the wearer is a safe person to which to turn.

Doug Bonney, chief counsel for the ACLU’s Kansas chapter, said telling staff last week not to wear the pins is “ludicrous.” He said litigation is “a very real probability” but that the organization wanted to give the district time to make a change first, with the school board expected to discuss the pins at a meeting next week.

Bonney added that any potential litigation is complicated by the fact that Kansas lawmakers eliminated due process for educators in 2014.

Bonney said staff in the district, which includes portions of several cities in suburban Kansas City, should be covered under the same free speech standard that applies to student speech. He referred to a 1969 U.S. Supreme Court ruling, Tinker v. Des Moines, which found high school students wearing black armbands to protest the Vietnam War were protected by the First Amendment’s free speech guarantees. The ruling allows for restrictions if the speech materially risks substantially disrupting schoolwork.

“If it is actually the district’s position that it is ‘disruptive’ to symbolically state that all students can feel safe and valued, that says something deeply disturbing and harmful about the culture and orientation of Shawnee Mission School District,” Micah Kubic, the ACLU of Kansas’s executive director, said in the letter.

The district, in a statement Monday along with the local union, stressed the importance of creating schools that “foster a culture of respect for all.” Employees’ communication inside the classroom “is considered speech on behalf of the school district” and that the pins had prompted complaints regarding “political connotations,” the statement read.

Marcus Baltzell, a Kansas National Education Association spokesman, said union was working with the district on the issue.

“What is disruptive is that at a time of fear and uncertainty, telling teachers and students secondarily that this is somehow a disruptive influence. Educators should be free to advocate for the safety of their students,” Baltzell said.

Kubic said he has heard that teachers have been told they would be face unspecified disciplined if they continued to wear the pins. Neither Kubric nor Baltzell were aware of any teachers who had faced discipline over the pins so far.

Jim Hinson, the district’s superintendent, said Tuesday the district’s admonishment of the safety pins followed other cases of potentially disruptive political symbols in its schools. Those instances included an employee who, after the Nov. 8 election, brought a Confederate flag to school for reasons unrelated to that class’ curriculum, Hinson said, adding that that employee honored administrators’ request to remove the flag and was not disciplined.

“Since we dealt with (that) one political symbol, we had to deal with all political symbols the same,” Hinson told The Associated Press. “We were aware of teachers in tears, accused of not being safe because they were not wearing safety pins. It really started snowballing.”

Hinson said he was unaware of whether any teachers on Tuesday were defying the request to stop wearing safety pins.