In gita, god says he has divided people into 4 varnas based on gunas.
Gunas are
1, Satvika - People who are not bothered about materialistic life leading a ascetic life. They were called brahmins. Brahmin is one who knows Brahman or god.
2, Rajasic - People who want power. They want land and wealth. Kshatriyas and vaishyas belonged to that.
3, Tamasic - People who are sloth, lazy, enjoying with women and drink all the time. Shudras belonged to that.
Bhagavt gita cleary says this. There were lot of hindu saints who has explained better than me what casteism in Hinduim is. It is never by birth.
After Vivekananda, there was no pan-indian Hindu leader who cud spread the essence of hinduism thruout India.
