Dancer in the Dark and Marx

How is Marx's theory of alienation displayed in the film Dancer in the Dark?

Alienation is the name of the game in Dancer. Our main character Selma takes on more hours and tougher tasks at her work as she secretly raises money to help her child not suffer the same fate as her. With being born with a optical disease that makes her go blind Selma works overtime at the factory she works in. As the days pass her eyesight lessens. She begins alienating herself from others around her as she obsesses over her daunting task at hand. Her relationships suffer and she becomes alienated from reality. She begins drifting off into surrealistic fantasies where everyone dances and sings. She has now lost herself in her labor by detaching herself from reality.

Why is Selma's alienation important to the central plot and the progression of the story?

When Selma sets herself apart from her family and friends and reality in general, she begins to set off the events that will ultimately lead her to her demise. If we follow the rules to any tragedy, our tragic hero (Selma) must have a tragic flaw. This character flaw will lead our character down a slippery slope that will result in her dying. The tragic hero doesn't know about her untimely demise and she doesn't know that she will be the one who causes her death. In Selma's case because she growing increasingly more blind she gets taken advantage of by Bill. He steals her savings and this causes the fight that sends Selma to jail and eventually death row.