The men in Vedic society who engage in public sanitary activities like picking up stool and sweeping the street are called hāḍis. Sometimes they are untouchable, especially when engaged in their profession, yet such hāḍis also have the right to become devotees. This is established by Śrī Bhagavad-gītā (9.32), where the Lord declares:
māṁ hi pārtha vyapāśritya
ye ‘pi syuḥ pāpa-yonayaḥ
striyo vaiśyās tathā śūdrās
te ‘pi yānti parāṁ gatim
“O son of Pṛthā, those who take shelter in Me, though they be of lower birth-women, vaiśyas [merchants], as well as śūdras [workers] can approach the supreme destination.”
There are many untouchables of the lower caste in India, but according to Vaiṣṇava principles everyone is welcome to accept this Kṛṣṇa consciousness movement on the spiritual platform of life and thus be freed from trouble. Equality or fraternity on the material platform is impossible.
When Lord declares, tṛṇād api su-nīcena taror iva sahiṣṇunā, He indicates that one must be above the material conception of life. When one thoroughly understands that he is not the material body but a spiritual soul, he is even humbler than a man of the lower castes, for he is spiritually elevated. Such humility, in which one thinks himself lower than the grass, is called su-nīcatva, and being more tolerant than a tree is called sahiṣṇutva, forbearance. Being situated in devotional service, not caring for the material conception of life, is called amānitva, indifference to material respect; yet a devotee thus situated is called māna-da, for he is prepared to give honor to others without hesitation.
Mahatma Gandhi started the hari-jana movement to purify the untouchables, but he was a failure because he thought that one could become a hari-jana, a personal associate of the Lord, through some kind of material adjustment. That is not possible. Unless one fully realizes that he is not the body but a spiritual soul, there is no question of his becoming a hari-jana.
Ref >> Srila Prabhupada Vani.