[1] Lapointe was elected by acclamation to the House of Commons of Canada for the riding of Kamouraska as a Liberal through a by-election on February 12, 1904.

From 1924 to 1930 as justice minister, Lapointe expressed his support for King's commitment to Canadian autonomy and accompanied him at the Imperial Conference of 1926.

During the 1939 provincial election, Lapointe made many speeches in the province of Quebec, in which he argued that if Duplessis was to be re-elected, every French Canadian minister would resign from the federal cabinet, leaving it without a francophone voice.

Duplessis lost in a landslide to Liberal Party of Quebec leader Adélard Godbout, who sought to co-operate with the federal government.

King decided to appoint the reluctant Quebec leading lawyer Louis St. Laurent to the cabinet as the new minister of justice.