Question: The 17th Premier of Nova Scotia and leader of the federal Progressive Conservative Party of Canada Robert Stanfield fought a few times and lost in general elections against which politician who is currently one of the longest-serving Prime Minister in Canadian history?
Sentence (from "Robert Stanfield"): Stanfield became the leader of the Nova Scotia Progressive Conservative Party in 1948, and after a rebuilding period, led the party to government in 1956.
Relevant evidence: No