Justin Trudeau took to the stage at the Liberal leadership race event Sunday to deliver his last message to the nation as prime minister after nearly a decade of service to Canada. He warned of the “existential crisis” Canada faces from the United States, where U.S. President Donald Trump has said he wants Canada to become the 51st state. “We are a country that will be diplomatic when we can, but fight when we must – elbows up!” Trudeau said, drawing chants and cheers of “elbows up!” from the crowd.