Question

People who take a "marble cake" view of federalism believe that

Answer 1

a view that holds the Constitution is a compact among sovereign states, so that the powers of the national governments and the states are clearly differentiated

Answer 2

ilikephysics2 is correct. To sum it up, marble cake federalists believe that there should/are very clear lines between state and federal government. Certain things should be handled at the state level and certain things should be handled at the federal level. They are two completely different "layers" in one big ball of "cake."