The U.S. Supreme Court declined to hear the case of Bradley Johnson, a calculus teacher at Westview High School in Rancho Penasquitos who had been fighting with the school district to keep his banners in place, The San Diego Union Tribune reported Tuesday.
The Supreme Court's decision settled the case in favor of the school district.
Johnson had been displaying the banners -- with slogans such as "In God We Trust," "God Bless America," and "God Shed His Grace on Thee" -- since 1982. In 2007, a school administrator told him the banners had to be removed because they did not follow Poway school district's non-religious education mission in public schools.
Then, in 2010, U.S. District Judge Roger Benitez ruled in Johnson's favor, concluding the district had infringed on his free speech rights.
The 9th U.S. Circuit Court of Appeals reversed that decision a year later, ruling public employers can limit what employees can say in the workplace.
Johnson finally took the cause to the Supreme Court, which declined to review the appellate court's ruling without comment on March 26.
The banners have since been removed from Johnson's classroom, a spokeswoman for the Poway school district said.