On what basis did the majority of the court of justices find school prayer unconstitutional?

The majority of the court justices found school prayer unconstitutional primarily on the basis that it violated the Establishment Clause of the First Amendment, which prohibits the government from establishing an official religion or unduly favoring one religion over another. They argued that state-sponsored prayer in public schools effectively coerces students to participate in religious activities, thereby infringing upon individual religious freedoms. The ruling emphasized the need to maintain a separation of church and state in public education to ensure that all students, regardless of their religious beliefs, feel included and respected.