while La Guardia came out in opposition to collective bargaining, the closed shop and the right to strike for public employees. In 1941, the Nazi invasion of the Soviet Union changed the Party's opinion of strikes, though it would be simplistic to treat this change in strategy solely as the result in the change in Comintern policy. Throughout his career, Quill preferred to threaten strikes as leverage to calling them and provoking a decisive test of strength. In addition, the union leadership had reservations in 1941 about the depth of its support among the general public and the employees of the IRT and BMT, many of whom believed that civil service protections gained as employees of the City made union representation less critical. National CIO leaders and the Franklin Delano Roosevelt administration intervened in 1941 to avert a subway strike with an ambiguous agreement that preserved TWU's right to represent its members, even though the City continued to deny it exclusive representation. Breaking with the CP The pressure on CP-led unions intensified after the end of World War II. These pressures fell especially hard on the TWU: the government arrested Santo for immigration law violations, and began proceedings to deport him. At the same time, Quill found the CP's political line increasingly hard to take, since it required him to oppose a subway fare increase that he considered necessary for wage increases in 1947, while the CP's support for the candidacy of Henry Wallace threatened to split the CIO. When William Z. Foster, then the general secretary of the CPUSA, told him that the party was prepared to split the CIO to form a third federation and that he might be the logical choice for its leader, Quill decided to break his ties to the CP instead. Quill applied the same energy to his campaign to drive his former allies out of the union that he had during the union's organizing drives of the 1930s. He was able to enlist new Mayor of New York City William O'Dwyer (a native of County Mayo back in Ireland), to his support, winning a large wage increase for subway workers in 1948, thus cemented his standing with the membership. After a few inconclusive internal battles, Quill prevailed in 1949, purging not only the officers who had opposed him, but much of the union's staff, down to its secretarial employees. Postwar years Unlike some