Final answer:
The shared constitutional clause in Abington v. Schempp and Engel v. Vitale is the Establishment Clause of the First Amendment. The facts of each case involved government-endorsed religious activities in public schools, which led to the Supreme Court declaring those practices unconstitutional. To limit the impact of Abington v. Schempp, the public might pursue legislative changes or shift towards private or home-school education.
Step-by-step explanation:
The constitutional clause common to both Abington 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, which includes policies or practices that promote or endorse religious practices within public institutions.
Because of the Establishment Clause, the facts of both Engel v. Vitale and Abington v. Schempp led to a similar holding, as both cases involved public schools promoting religious activities - prayer and Bible reading, respectively - which the Supreme Court ruled as unconstitutional. The mandatory nature of these religious activities in public schools represented a government endorsement of religion, thus violating the Establishment Clause.
Members of the public who disagree with the court's decision in Abington v. Schempp could engage in various actions to limit its impact, such as advocating for constitutional amendments, lobbying legislators to pass laws that test the boundaries of the Establishment Clause, or promoting private and home-school education where religious activities can be more freely incorporated.