WASHINGTON (Reuters) -The U.S. Supreme Court declined on Monday to hear a case involving a Massachusetts public school teacher who sued on free speech grounds after her school fired her in what she called retaliation for social media posts made prior to her employment.

The justices turned away plaintiff Kari MacRae's appeal of a lower court's rejection of her lawsuit seeking monetary damages from Hanover Public Schools and school officials. The lower court found that the officials and district did not violate the U.S. Constitution's First Amendment protections against government abridgment of freedom of speech, as MacRae claimed.

MacRae was fired in 2021 after school officials discovered a half dozen social media posts that she liked, shared, posted or reposted with her TikTok account, characterized by the officials as memes containing "themes of homophobia, transphobia and racism."

According to court records, one meme showed a photo of Rachel Levine, a transgender woman who served as the U.S. assistant secretary for health during Democratic President Joe Biden's administration, with text that reads: "'I'm an expert on mental health and food disorders.' ... says the obese man who thinks he's a woman." Another meme showed a photo of a muscular, bearded man wearing a sports bra with text that reads: "Hi my name is Meagan, I'm here for the Girl's track meet."

Another displayed a photo of a panda with text that reads: "Dude, racism is stupid. I am black, white, and Asian. But everyone loves me," according to court records.

The disputed posts came months before MacRae was employed by the school, according to court records.

MacRae is currently running as a Republican for a seat in the Massachusetts state Senate.

Also before her hiring, MacRae posted a video on TikTok in 2021 as part of her successful bid for a school board position in a different school district in which she said that "critical race theory" should not be taught in public schools and that students should not be "taught that they can choose whether or not they want to be a girl or a boy."

MacRae was fired about a month after the school district hired her as a math and business teacher. School officials stated in MacRae's termination letter that "continuing your employment in light of your social media posts would have a significant negative impact on student learning" at the school.

In her lawsuit, MacRae accused Hanover Public Schools and school officials of unlawfully retaliating against her for speech protected by the First Amendment.

The dispute implicated a 1968 Supreme Court ruling involving the First Amendment rights of public employees. The court in that case ruled that while public employees do not forfeit their right to express themselves on matters of public importance, an employee's free speech rights must be weighed against the government's interest in maintaining a workplace free from disruption.

A Boston-based federal judge in a 2023 ruling applied the prior Supreme Court ruling and determined that Hanover Public Schools had shown enough evidence of the potential for disruption to justify MacRae's firing. The judge also ruled that school officials were entitled to qualified immunity, a legal doctrine that broadly shields public officials from liability.

The Boston-based 1st U.S. Circuit Court of Appeals upheld that ruling, prompting MacRae's appeal to the Supreme Court.

MacRae argued that the Supreme Court's prior ruling should not apply to her case since it involved comments made by an employed teacher, while MacRae's disputed social media posts were made prior to her employment by Hanover Public Schools.