Before the outbreak of WWII, the Muslim League didn't have much political support and the Indian National Congress almost had the monopoly of popular support. In the provincial elections conducted in 1937, the Congress had swept almost all the provinces including the Pakhtoon region (thanks to Khan Abdul Gaffar Khan). When the World War started and the Viceroy declared that India too was a part of it without consulting the Congress, all the provincial ministries of Congress resigned and Mahatma Gandhi proclaimed the Quit India movement. All the Congress leaders were jailed and the activities of the Congress were suppressed. This gave Jinnah and his Muslim League who supported the Government total freedom to travel across the country and spread their message without any resistance. By the time, the WWII was over and the restrictions over the Congress were removed, the League had become much stronger. Jinnah raised his demand for a separate homeland for Muslims and the British Government gave him covert support. In a scenario where WWII hadn't occurred or India had won independence before WWII, chances for the partition were very weak. The slogan of 'Pakistan' gained popularity only after it was taken over by Jinnah and that too during and after the WWII.