Because it lets them have equal say with other states
Explanation:
States with smaller populations favor having a set number of representatives in Congress because it allows them to still have an influence on politics. If representation in a body of power depends on population size, then the states with a larger population will have more representatives, and therefore the interests of the larger states will be pushed more, while the smaller states' voices will be drowned out. Larger states would most likely prefer representation based on population because it gives them more say on politics and because it serves the interests of the majority of the overall population.
