Tom Buchanan goes on a rant about how "civilization's going to pieces." According to Tom, What is the cause of this perceived problem?

Tom thinks that the rising number of people of color are threatening the white race. He believes the white race created civilization, and that other races want to seize control over it, which threatens the culture, art, and science.

Explanation:

Tom thinks that “other races” are submerging the white, dominant race and getting “control of things” slowly. He cites the book called Coloured Empires as his source, which is obviously a quasi-intellectual book that promotes racists speculations. By this theory, the white race is connected to Nordic people who have produced technology, art, and science, meaning they have produced the whole civilization.

Tom believes that white rice will die out if they don’t do something, and that people of color will get to have control. He obviously sees this as an attack on himself and civilization, which reveals to us that he is an incredibly racist and hateful person.

the sentence that avoid faulty coordination is:

culture, which is well represented in philadelphia, plays a major role including theatre, music, and the visual arts.  

faulty coordination occurs when the writer gives equal importance two different ideas (clauses) which in fact are not equivalent. in order to correct a misplaced clause or idea, the writer can place less important or emphatic ideas in a relative clause as in the previous sentence.