On March 30, 1965, Ervin announced that he would offer a substitute to the Johnson administration's voting rights bill. Ervin referred to the administration's bill as cockeyed and unconstitutional, and that his version would provide for federal registers being appointed in areas certified to having findings of racial discrimination as defined under the Fifteenth Amendment to the United States Constitution. Ervin said he would seek approval of the Senate Judiciary Committee and that he would carry the fight to the Senate floor in case the committee rejected his legislation. Ervin was also a staunch opponent of the Immigration and Nationality Act of 1965 which abolished nationality quotas beginning in 1968. He felt that the principle of tying allowed numbers of immigrants from a given country to the number of people who had ancestral origins in that country and lived in the United States should be retained. Meanwhile, Ervin's strict construction of the Constitution also made him a liberal hero for his support of civil liberties, his opposition to "no knock" search laws, and the growing intrusions of data banks and lie-detector tests as invasions of privacy. In 1966, Senator Ervin played a major role in the defeat of Senator Everett Dirksen's Constitutional amendment to allow prayer in public schools. Ervin also favored the exclusionary rule under the Fourth Amendment, which made illegally seized evidence inadmissible in criminal trials. In November 1970, Ervin was one of three Senators (all from Southern states, the others being James Eastland and Strom Thurmond) to vote against an occupational safety bill that would establish federal supervision to oversee working conditions. When the Senate voted on the Equal Rights Amendment (ERA) in 1971, Ervin proposed an amendment that would exempt women from the draft; Ervin's amendment to the ERA overwhelmingly failed. However, he was a staunch opponent of the ERA, and after it passed the Senate Ervin used his influence to dissuade the North Carolina General Assembly from ratifying it, maintaining that it was the "height of folly to command legislative bodies to ignore sex in making laws". He became involved in Senate investigations before Watergate, when in January 1970 it was revealed by Christopher Pyle, an investigator for Ervin's Judiciary Subcommittee on Constitutional Rights, that the U.S. Army was performing domestic investigations on the civilian population. Ervin's further work in the matter over the following years, together with the Church Committee inquiries, led to passage