Vera Cruz, at the time also active in organizing the Filipino farmworkers across the West Coast region, would later recall that Seeking to implement concretethough nonetheless radicalchanges to the largely immigrant workers' conditions, the union elected a course of putting pressure on the business owners to win better pay, demand decent housing, and doing away with a system of "hold back" policy under which capitalist growers kept half of a worker's pay until the end of the growing season. The union chose to organize a workers' walkout, and, together with Chris Mensalvas, Mangaoang led the 1948 Stockton Strike in Stockton, California. As Communists, Mangoang and other leaders of the ILWU Local 7 were arrested in 1950two years after the Stockton Strikeand threatened with deportation under the U.S. government's anti-communist McCarran Act. The Filipino American historian and Marxist E. San Juan, Jr. observes that at this time Filipino trade unionists, bearing a special place in the history of the Cold War-era crackdowns, were "brought to trial, harassed, and threatened with deportation." The ILWU workers' union adopted a resolution condemning the prosecution of the labor activists, stating that It noted that even as Mensalvas was released under a writ of habeas corpus, Mangaoang was held for 70 days before winning the right to release on bail. Although he had been a citizen of the United States even prior to immigrating from the Philippines, the Court sought to deport Mangaoang back, citing as precedent the approved case of the deportation of Arcadio Cabebe, expelled as a non-citizen Filipino alien, as the United States had never granted United States citizenship to inhabitants of the Philippines when it semiformally annexed the islands. Mangoang's case, known as Mangaoang v. Boyd and proceeding all the way to the U.S. Supreme Court in 1953, was a rare victory against the Red Scare of the McCarthy years: the Court upheld the appeals court decision that Mangaoang could not be deported under the Walter-McCarran Act. The attempted deportation of Mangaoang and Mensalvas was successfully fended off by lawyers from the Communist Party USAthen itself facing McCarthyite repression and charged with violating the later-repealed sections of the 1940 Smith Act. Not wanting to bring further harassment on the ILWU and in disagreement over union activities with other members of the ILWU 37's leadership, Mangaoang resigned from the union ranks. Spending the remainder of his life working various jobs across the Northwest.