Rep King is a very ignorant person. Anybody who defends animal abuse or dog fighting on the grounds that human fighting isn't banned is too stupid to be in Congress (and that's a pretty low bar).
It is a VERY stupid thing to say. It's not like a dog could say "I don't want to do this". However, there is a danger to federalizing everything. Not every law needs to be a federal law.
I think that should happen only when State Laws fail.