Complex sentence: The Communists were able to persuade the Social Democrats to hold elections in factories were the communists held the majority, the clear majority results gained by the communists during this election prompt the Social Democrats to postpone the rest of the election.
Split into simpler sentences: The Communists were able to persuade the Social Democrats to hold elections in factories where the communists held the majority. The clear majority results gained by the Communists during this election prompted the Social Democrats to postpone the rest of the election.