He came to prominence first with his book Seeds of Treason, co-authored with Ralph de Toledano, in which the authors argued in favor of Whittaker Chambers over Alger Hiss.
He was one of the first journalists to write a critical view of President John F. Kennedy. His 1963 book JFK: The Man And The Myth also took a negative viewpoint of the popular young president. Lasky questioned Kennedy's wartime heroics on the PT-109 and claimed he had a lackluster record as a congressman and senator. Lasky also wrote a similar negative book about Robert Kennedy.
Lasky's most controversial book was It Didn't Start With Watergate published in 1977. The author argued that the scandal that drove Richard Nixon from office was little more than a media event. He believed that the press disliked Nixon and subjected him to unfair scrutiny no other president had ever experienced. Lasky also claimed that Franklin D. Roosevelt had used wiretaps on political opponents as well as John F. Kennedy and Lyndon B. Johnson.
Lasky professed the greatest political "crime of the century" was not Watergate but what he describes as the "theft" of the 1960 Presidential election.
In 1979, Lasky wrote another controversial work called Jimmy Carter: The Man And The Myth, asserting that Carter was one of the most inept presidents of all time.
Lasky's last work was Never Complain, Never Explain (1981), a biography of Henry Ford II.