Various public officials had supported lowering the voting age during the mid-20th century, but were unable to gain the legislative momentum necessary for passing a constitutional amendment.
The drive to lower the voting age from 21 to 18 grew across the country during the 1960's and was driven in part by the military draft held during the Vietnam War.
The draft conscripted young men between the ages of 18 and 21 into the United States Armed Forces, primarily the U.S. Army, to serve in or support military combat operations in Vietnam.
The Supreme Court subsequently held in the case of Oregon v. Mitchell that Congress could not lower the voting age for state and local elections.
[3] The framers of the U.S. Constitution did not establish specific criteria for national citizenship or voting qualifications in state or federal elections.
The slogan traced its roots to World War II, when President Franklin D. Roosevelt lowered the military draft age to 18.
[8] Historian Thomas H. Neale argues that the move to lower the voting age followed a historical pattern similar to other extensions of the franchise; with the escalation of the war in Vietnam, constituents were mobilized and eventually a constitutional amendment passed.
[10][11] Increasing high-school graduation rates and young people's access to political information through new technologies also influenced more positive views of their preparation for the most important right of citizenship.
[10] Between 1942, when public debates about a lower voting age began in earnest, and the early 1970's, ideas about youth agency increasingly challenged the caretaking model that had previously dominated the nation's approaches to young people's rights.
In his own interpretation of Katzenbach, Nixon argued that to include age as a possible parameter of discrimination would overstretch the concept, and voiced concerns that the damage of a Supreme Court decision to overturn the Voting Rights Act could be disastrous.
[20] In Oregon v. Mitchell (1970), the Supreme Court considered whether the voting-age provisions Congress added to the Voting Rights Act in 1970 were constitutional.
[10] Professor William G. Carleton wondered why the vote was proposed for youth at a time when the period of adolescence had grown so substantially rather than in the past when people had more responsibilities at earlier ages.
[24] Carleton further criticized the move to lower the voting age, citing American preoccupations with youth in general, exaggerated reliance on higher education, and equating technological savvy with responsibility and intelligence.
[32] On March 2, 1971, Bayh's subcommittee and the House Judiciary Committee approved the proposed constitutional amendment to lower the voting age to 18 for all elections.
Contemporaneous reports agree that Ohio's House of Representatives cast the decisive vote on the evening of June 30, and that Alabama and North Carolina had ratified the amendment earlier in the day.
President Nixon and Julianne Jones, Joseph W. Loyd Jr., and Paul S. Larimer of the "Young Americans in Concert" also signed the certificate as witnesses.