Complex sentence: He was the Ontario CCF's candidate in the west-end Toronto riding of High Park in the 1943 Ontario election but was defeated by George Drew, leader of the Ontario Progressive Conservative Party who became Premier of Ontario as a result of the election.
Split into simpler sentences: He was the Ontario CCF's candidate in the west-end Toronto riding of High Park in the 1943 provincial election, but was defeated by George Drew, leader of the Ontario Progressive Conservative Party. Drew became Premier of Ontario as a result of the election.