Whites in the South fought hard to prevent integration. Was there an economic motive as well as an ideological one? Did whites as a whole profit from Jim Crowe? Or did freeing up the economy for some 20% of the population provide economic growth for both races?
Michael Honey lays out a very good case for the economic motives of Southern whites in regards to segregation in this book "Southern Labor and Black Civil Rights". The answer is, some white heavily profited off of segregation while other whites suffered almost as much economically as black labor did. White merchants and business leaders were basically able to pit whites against blacks to keep them from unionizing together. If you could get white workers to refuse to allow blacks into their unions, you always have a very steady force of strikebreakers should white unions decide to strike for better wages. This only furthers the racial tensions between blacks and whites because blacks are seen as taking white jobs in white industries. So not only are blacks continually marginalized, white labor unions are discouraged from striking and demanding better pay. This suppresses wages all around and benefits business owners.
I highly recommend Honey's book. It is focused more on labor organization in the South, but it is a fascinating picture of how whites and blacks were manipulated by segregation to work against their own best interests.