How did the westward expansion fuel the argument over slavery in the United States?

Because the south want to expand more to west and bring their slaves with them for more land to start the reproduction of plantations on the west

Opposition to the nra came to a head in 1935, when the conservative supreme court declared the agency unconstitutional, claiming the nra gave the executive branch regulatory powers that belonged exclusively to congress. this decision began a series of court decisions that overturned key elements of the new deal.