Final answer:
The Establishment Clause of the First Amendment is the common clause in both Abington School District v. Schempp and Engel v. Vitale, leading to similar rulings due to the unconstitutional endorsement of religion in public schools. To limit the impact of these decisions, the public could advocate for legislative changes or voluntary religious activities that comply with constitutional mandates.
Step-by-step explanation:
The constitutional clause common to both Abington School District v. Schempp and Engel v. Vitale is the Establishment Clause of the First Amendment. This clause prohibits the government from making any law respecting an establishment of religion, thus ensuring a separation of church and state. Both cases led to a similar holding because the Supreme Court found that requiring students to participate in religious exercises is an endorsement of religion by the state, violating this constitutional clause.
Members of the public who disagree with the Court's decision in Abington v. Schempp could take various actions to limit its impact. These actions could include lobbying for legislation that would introduce moments of silence instead of prayers, advocating for voluntary after-school religious programs, or pushing for constitutional amendments that allow for religious activities in schools under certain conditions.