Bernstein's parents Sylvia and Alfred, both members of the American Communist Party, were called to testify before the House Un-American Activities Committee (HUAC) and the Senate Subcommittee on Internal Security in the 1950s and were under FBI surveillance for four decades.

[1] Loyalties recounts Bernstein's family's life in the 1940s and 1950s, during which his parents' left-wing activism and involvement in the labor movement brought them under heavy scrutiny from the FBI and the United States Congress.

[2] In 1947, President Harry S. Truman signed Executive Order 9835, which created 150 loyalty boards to investigate federal employees and to dismiss those found to be disloyal to the U.S. government.

Clifford admitted to Bernstein that there had been no serious threat of communist infiltration of the federal government and that the Truman administration's loyalty program was created to fend off accusations from the Republican Party of being "soft" on communism.

Publishers Weekly called it a "pained, loving, intensely felt account of his parents' ordeal, and his own emotional upheaval, during President Harry Truman's loyalty purges".

"[8] The New York Times gave Loyalties a similarly mixed assessment, praising Bernstein's retelling of childhood memories and his portrait of the Washington Jewish community but criticizing his historical and political analysis.

[9] In the Los Angeles Times, historian Eric Foner said that "Loyalties fails both as autobiography and as political analysis" but praised Bernstein for "[driving] home a truly subversive idea: Rather than a nest of spies, the Communist Party was an integral and honorable part of the American radical tradition.