During the campaign, Nixon also used as a theme his opposition to the decisions of Chief Justice Earl Warren. Many conservatives were critical of Chief Justice Warren for using the Supreme Court to promote liberal policies in the fields of civil rights, civil liberties, and the separation of church and state. Nixon promised that if he were elected president, he would appoint justices who would take a less-active role in creating social policy. In another campaign promise, he pledged to end the draft. During the 1960s, Nixon had been impressed by a paper he had read by Professor Martin Anderson of Columbia University. Anderson had argued in the paper for an end to the draft and the creation of an all-volunteer army. Nixon also saw ending the draft as an effective way to undermine the anti-Vietnam war movement, since he believed affluent college-age youths would stop protesting the war once their own possibility of having to fight in it was gone.