The clock ran down at the end of the homecoming game and spectators stormed the football field, knocking over members of the high school band — all to gather around an assistant coach as he took a knee in prayer, surrounded by uniformed players.

Six years later, after losing his coaching job and repeatedly losing in court, that former Washington state coach, Joe Kennedy, will take his arguments before the U.S. Supreme Court on Monday, saying the Bremerton School District violated his First Amendment rights by refusing to let him continue praying at midfield immediately after games. Four conservative justices have already expressed concerns with how his case has been handled.

Kennedy’s effort to get his job back helped earn him an appearance at a 2016 Donald Trump rally and quickly became a cultural touchstone, pitting public school employees’ religious liberties against what his critics describe as longstanding principles separating church and state and protecting students from religious coercion.

Lawyers for the school district say officials had no problem letting Kennedy pray separately from students or letting him return to the field to pray after the students left. But allowing him to pray at midfield immediately after games with students there risked being seen as government endorsement of religion.