TORONTO-(CP)-The decision Tuesday by a third Liberal cabinet minister from Quebec not to seek the Liberal leadership is casting a spotlight on the party’s ability to organize support in a province that has long been crucial to its electoral success. Industry Minister François-Philippe Champagne announced at a luncheon discussion in Toronto that he won’t be on the ballot when the Liberals choose their new leader on March 9. Champagne, long seen as a potential successor to Trudeau, said instead of running he will focus on ensuring the government is ready to protect Canadian industry from the trade threats posed by incoming U.S. president Donald Trump. “It was probably the most difficult decision of my life, but I think it was the right one at the right time,” Champagne said. “There…