On April 10, 1967, appearing with co-counsel Philip Hirschkop on behalf of the ACLU, Cohen presented oral argument for the petitioners in Loving v. Virginia before the U. S. Supreme Court.
[3] On June 12, 1967, the Supreme Court ruled in favor of Cohen's clients, declaring bans on interracial marriage unconstitutional, thus invalidating the anti-miscegenation laws of 15 states.
In an interview, Cohen associated his father's union activities with his own respect for working people and his status as a historically oppressed minority as an impetus for furthering equal rights.
[10][11][12] After the passage of the Civil Rights Act of 1964, Mildred wrote U.S Attorney General Robert F. Kennedy, inquiring whether the new federal law would allow her and her husband to live in Virginia again.
The opinion declared that bans on interracial marriage were unconstitutional, depriving both partners of equal protection under the law, as guaranteed by the U.S. Constitution's Fourteenth Amendment.
[4] In early 1983, Cohen backed a nuclear freeze resolution before the Virginia State Senate Rules Committee, which ultimately was voted down 10–4 on February 8.
Cohen's resolution decried the "huge sums of money being spent testing, producing, and deploying nuclear warheads and weapons" and the strain it placed on the rest of the federal budget.
The measure allowed terminally ill patients to determine whether they wanted to go through "heroic artificial means to keep their bodies alive when there was no hope of recovery".
[20] In February 1984, Cohen strongly opposed a bill that prevented young men who had not registered with the Selective Service System from attending state colleges and receiving financial aid.
[21] Cohen co-authored a blog entry in 2007 for the Huffington Post invoking his experience in Loving v. Virginia to support the legalization of same sex marriage.