Carter is Policy Director and Board Member of the Fair Start Movement, an organisation dedicated to giving every child a fair start in life. He is the author of Justice as a Fair Start in Life. Carter began his career as an Honors Program appointee to the U.S. Department of Justice. He later served as a legal adviser to the U.S. Department of Homeland Security, in the national security law division. He wrote his thesis reformulating the right to have children under Jeremy Waldron, his extensive academic work on family planning has been published by Yale, Duke, and Northwestern Universities, as well as in peer-reviewed pieces.. He has served on the Steering Committee of the Population Ethics and Policy Research Project and was a Visiting Scholar at the Uehiro Center, both at the University of Oxford. He has taught at several law schools in the U.S., served as a peer reviewer for the journal Bioethics, and most recently managed an animal protection strategic impact litigation program.
Carter is vegan and has a naturalistic worldview.