Question

Why do you think representation was such a difficult issue to resolve?

Answer 1

Different states had different opinions about what the representation laws should be. This lead to two comprimises the 3/5 ths comprimise and whats known as The Great Comprimise

Answer 2

I guess it is because people have different views on what equality exactly is. For example, states couldn't figure out what equality is when determining the representation inside the legislative branch: whether equal representation from states or equal representation based on the population.