Langevin was Cartier's successor as Quebec lieutenant to Sir John A. Macdonald and de facto leader of the federal Conservative Party in French Canada.

Tarte himself sat as a member of the Quebec legislative assembly from 1877 to 1881 in the riding of Bonaventure and made moderate Conservative Joseph-Adolphe Chapleau, Langevin's rival, a frequent target of both speeches and editorials.

Tarte chose not to run for re-election in 1881, partly due to being disconcerted by the Vatican's warnings against clerical influence in politics which would be synthesized in 1885 in the Encyclical Immortale Dei.

He played the leading role in exposing the McGreevy-Langevin scandal that resulted in McGreevy's expulsion from the House of Commons for corruption and forcing the resignation from Cabinet of Langevin, his former mentor.

Tarte was unseated in 1892 due to a court challenge to his election but re-entered parliament the next year as an independent and was soon invited by Wilfrid Laurier to join the Liberals.