I think the most intense significance of Gandhi's fasts to protest the treatment of untouchability was to highlight that his movement was one of moral and ethical transformation. Gandhi clearly identified himself with one who believed in a spiritual transformation of those who followed him. At a time when so many believed in the pure politics of the Indian Independence Movement, Gandhi argued that political change is secondary to moral or ethical transformation. This caught people by surprise, given the highly politicized nature of the time period. However, when Gandhi fasts against the practice of untouchability it becomes a symbolic action that shows that ethical and moral change can apply to everyone. Had Gandhi been a pure political being, he would not have embraced the idea of fasting to eradicate untouchability, something that is purely an Indian construct and little to do with the British. Rather, Gandhi speaks to the idea that change can only happen when people initiate change in themselves. His fasting for spiritual change, the notion that human beings not create caste based systems that deny another human's voice, is where he can be seen as more than just a political leader. In this, his significance is profound in making the political movement of a free India a moral or spiritual one, as well.
Rejection of the traditional unfair caste system.