After receiving his MPA from the University of Minnesota, Segal moved to Washington, D.C. in 1974 to work as an aide to Congressman Donald M. Fraser and administrator of the House Budget Committee's task force on distributive impacts of economic policy. In 1979, he became Coordinator for the Near East in the policy bureau of the US Agency for International Development and, later, Senior Advisor for Agency Planning. After leaving government, he joined the Institute for Philosophy and Public Policy at the University of Maryland as Senior Research Scholar. Segal has been a leader of the American Jewish peace movement, starting in 1982 with Washington Area Jews for Israeli-Palestinian Peace, a group that opposed the Israeli invasion of Lebanon. In 1987, he traveled to Tunis to meet Yasser Arafat and leaders of the Palestine Liberation Organization. No American Jewish delegation had ever met with the PLO, which the U.S. government officially considered a terrorist organization at the time. In August 1988, Israel raided the offices of Faisal al-Husseini, a Palestinian militant, and discovered a plan, based in part on earlier writings by Segal, for a ''declaration of Palestinian independence." That plan, along with other writings by Segal in Palestinian papers such as Al-Quds, were a catalyst for the Palestinian Declaration of Independence later that year and the Palestinian peace initiative in which Israel's right to exist was recognized. In May 1989, Segal founded the Jewish Peace Lobby, which he envisioned as acting as a counterweight to the American Israel Public Affairs Committee. The Peace Lobby remains active today, with about 5,000 members.
As a candidate
In 2018, Segal announced the creation of a new socialist political party called "Bread and Roses", after raising the requisite 10,000 signatures needed by the Maryland Board of Elections. The party is named after a slogan used by striking workers during the 1912 Lawrence textile strike. Segal ran for a seat in the US Senate against Ben Cardin in the 2018 mid-term elections. After losing in the Democratic primary to Cardin, he attempted to be included in the general election under the Bread and Roses party, but was prohibited due to the "sore loser" statute of Maryland state law, which prohibits candidates from running in the general election after losing a primary. After the 2018 election, Segal submitted a petition with more than 15,000 signatures to the Maryland Board of Elections. The Board certified the Bread and Roses party in January 2019, allowing its candidates to run for office in Maryland in the 2020 election. In August 2019, Segal announced that he would run for president under the Bread and Roses party. He said that he would not compete in swing states to avoid taking votes from a Democratic candidate running against Donald Trump. The Bread and Roses party identifies itself as "socialistic" in nature, distinguishing itself from traditional socialism. The party advocates socialist ideals, like "From each according to his abilities, to each according to his needs," while also advocating democratic principles of limited government, individual liberty, and rule of law. Their website also advertises ideals like "plain living, high thinking" and a Utopian future.