I think their experience during the Great Depression was amplified by the spread of racial discrimination. Almost half of them were unemployed and often lose their jobs during that time. This kind of situation they are into was not new. It has been a part of their life which they don't associate with the national economic situation.
But the rate of violence that they experience increased in this period and gave further pressure to them. On the other hand, the Indian New Deal in 1934 gave the Indians funding for their economic development.