On 16 August 1931, the first anniversary of his inauguration, Trujillo made the Dominican Party the nation's sole legal political party. However, the country had effectively become a one-party state with Trujillo's inauguration. Government employees were required by law to "donate" 10 percent of their salaries to the national treasury, and there was strong pressure on adult citizens to join the party. Members had to carry a membership card, nicknamed the "palmita" since the cover had a palm tree on it, and a person could be arrested for vagrancy without one. Those who did not join or contribute to the party did so at their own risk. Opponents of the régime were mysteriously killed.