Complex sentence: Ourso claimed that he had won the Democratic primary election held on December 7,1963, because he led by a plurality, and a third candidate who had withdrawn from the race still received enough scattering of votes to prevent an Ourso majority.
Split into simpler sentences: Ourso claimed that he had won the Democratic primary election held on December 7,1963, because he led by a plurality. A third candidate who had withdrawn from the race still received enough scattering of votes to prevent an Ourso majority.