Campbell first ran for a
seat in the
Legislative Assembly of Prince Edward Island in a 1930 by-election as the
Liberal candidate in
2nd Prince but lost. In 1930, he was appointed Attorney General of Prince Edward Island. He was elected for
1st Prince in
1931 and re-elected in
1935 and was appointed Attorney and Advocate General in Premier
Walter Lea's cabinet. When Premier Lea died in 1936, Campbell succeeded him. Campbell's government organised the provincial police, passed the province's first law governing the
public service and established a
national park. With the beginning of
World War II, Campbell's government committed itself to organising the province for the war effort. ==Judicial career==