Complex sentence: After losing the Quebec Liberal Party leadership race to Robert Bourassa in 1970, Wagner left politics to return to the bench but then jumped to federal politics, being elected as a Progressive Conservative MP in the 1972 federal election.
Split into simpler sentences: After losing the Quebec Liberal Party leadership race to Robert Bourassa in 1970, Wagner left politics to return to the bench. He then entered federal politics, and was elected as a Progressive Conservative Member of Parliament in the 1972 federal election.