In 1968, the Soviet invasion of Czechoslovakia divided the 120-member leadership of the CPUSA. All but three of the National Committee, headed by party leader Gus Hall, backed the intervention of Soviet tanks. A meeting of the National Committee held over the Labor Day weekend backed Hall by a margin of five-to-one. Bettina Aptheker denounced the invasion, however, and voted with the minority; she opposed her father Herbert Aptheker over this issue. One of the CPUSA's leading intellectuals, he and a majority of its leaders had defended the Soviet intervention in Hungary in 1956.