Maclean believed that Scottish workers were especially fitted to lead the revolution, and talked of "Celtic communism", inspired by clan spirit. But his launch of a Scottish Workers Republican Party and a Scottish Communist Party were largely unsuccessful. Although he had been appointed Bolshevik representative in Scotland, he was not in harmony with the Communist Party of Great Britain, even though it had absorbed the British Socialist Party, to which he had belonged. In captivity, Maclean had been on hunger strike, and prolonged force-feeding had permanently affected his health. He collapsed during a speech and died of pneumonia, aged forty-four.