The federalized nature of American government means both things can be true simultaneously, even though they seem paradoxical when placed together in juxtaposition. The Feds have supremacy in certain matters, but not all.

Moreover, lobbying is more a question of connections and relationships which are lubricated with money than pure spending power, so it can be easier for a large corporation to nudge things its way at the national and state levels while still struggling to curry influence at the local level, and vice versa for small companies.