Background: 1952. The U.S. Supreme Court (in Zorach v. Clauson) allowed public school children to be released for one hour a week for religious instruction.
In 1981, the Tenth Circuit ruled that schools could additionally give credit for having taken an elective for released-time religious education.

In Spartanburg S.C., a high school has been accepting academic grades for this release time religious "class". This means a student can get an A+ for whatever reason the religious school wants to give an A+ for ("exceptional piety", for example). That grade is then accepted at face value by the public school, and the student can gain an academic advantage.

Once this "easy A" was discovered, enrollment sky-rocketed. High school students hardly needed to be recruited to participate in the "South Carolina Bible Education in School Time" program.

Two students protested and have filed a lawsuit against the Spartanburg County School District challenging the awarding of said academic credits as a violation of the Establishment Clause of the First Amendment. After much opposition, harassment, letters to editor, etc., the suit has finally been allowed to continue (by the U.S. District Court in S.C.).

Now we wait for the outcome, whenever the court ever gets around to making a decision. Stay tuned.