Pope Paul VI created him Cardinal-Priest of S. Lucia a Piazza d'Armi in the consistory of March 5, 1973. During the Vietnam War, Manning counseled young men on their right to become conscientious objectors. Staunchly anti-abortion, the Archbishop declared that any Catholic who cooperated in an abortion would suffer excommunication from the Church, including the mother herself. In 1974, in response to the Supreme Court's ruling on "Roe v. Wade", he testified before the Subcommittee on Constitutional Amendments of the Senate Judiciary Committee, saying, "An amendment is necessary first of all to protect the lives of the unborn children who can be killed—indeed, are being killed at this very moment—in the wake of the Supreme Court's decisions. But it is also needed to restore integrity to the law itself, to make the American legal system once more the guarantor and protector of all human rights and the human rights of all."