How it is possible to make a chandala a Vaisnava!" No, that is possible. Prabhavisnave namah. Visnu is so powerful, omnipotent. He can do that. So only by Visnu mantra, by becoming a Vaisnava, one can transcend all this restriction, sociology
-Lecture on Bhagavad-Gita 1.40 -- London, July 28, 1973

प्रयाणकाले मनसाचलेन
भक्त्य‍ा युक्तो योगबलेन चैव ।
भ्रुवोर्मध्ये प्राणमावेश्य सम्य-
क्स तं परं पुरुषमुपैति दिव्यम् ॥ १० ॥
One who, at the time of death, fixes his life air between the eyebrows and, by the strength of yoga, with an undeviating mind, engages himself in remembering the Supreme Lord in full devotion, will certainly attain to the Supreme Personality of Godhead.
-Bhagavad-Gita Chapter 8 Verse 10