The movement to formalize the exclusion of Asians from America was gaining momentum. The Chinese had already been excluded through the Chinese exclusion act in the late 1800's.  The Immigration Act of 1917, prohibiting immigration from an Asian "barred" zone and imposing literacy restrictions, along with the Oriental Exclusion Act of 1924, banning most immigration from Asia, slowly stifled immigration from India. 

The exclusionists had achieved most of their goals by now. Asian and Indian immigration was virtually banned. However, this wasn't enough. A movement was mounted to deny citizenship to the Indians in the U.S., take away the citizenship from Indians who had already been granted citizenship and to apply the Regional Exclusion Act retroactively to deport all Indians in the U.S.

It worked partially. A large number of Indians left. Many of them were denied citizenship, with the Supreme Court upholding one such decision that was challenged. On February 19, 1923, with Justice George Sutherland delivering the opinion, the Supreme Court held that East Indians were not eligible for United States citizenship because they could not be considered white or Caucasian. A few Indians lost their citizenship.

Resource and Links:

United States v. Bhagat Singh Thind - Wikipedia