 With the presidency vacant and according to the constitution then in force, enacted in 1946, Quadros should have automatically been replaced by Goulart.However, because Goulart was on a diplomatic trip to the People's Republic of China at the time, and because, although a moderate nationalist, Goulart was accused of being a communist by right-wing militants, he was unable to take office.After lengthy negotiations, led mainly by Tancredo Neves, Goulart's supporters and the right-wing reached an agreement under which the parliamentary system would replace the presidential system in the country.