. What does Karl Lindner’s visit add to the Younger family’s troubles?

Basically Karl Lindner represents the white community and their overt racism. They do not want Mama's (a black family) moving into their neighbourhood. He and his fellow homeowners raise the money to effectively buy the house the House that Mama bought for more than what she had paid for it. THis guy only perpetuates the cycle of racism and poverty the Youngers must endure.