Defense is a good guess, especially given the current President and the near even split in the Congress. So are the others: alcohol, tobacco, lawyers are a big one, so are unions, but no one got it yet.
So I'll tell you:
Pharmaceuticals. Not to be confused with healthcare, because that encompasses doctors and hospitals and the like.
Just plain old pharmaceuticals.
These are the organizations most responsible for our war on drugs, after all, they make the drugs we "can" use.
They can sell heroin-strength narcotics like oxycontin (sp?), mind altering drugs like Prozac, Zoloft and Luxor, and a whole bunch of other chemicals which are prescribed by doctors who face ever dwindling salaries.
But if I want to medicate myself with a little marijuana, well....guess what: no can do. Want to increase my serotonin with some powdery white shit, I could go to jail.
Anyway I just thought I would throw some Friday afternoon silliness on there....as you ponder the impact of this lobbying on the way to happy hour, factor this in: The number 2 lobbying industry is Insurance.
It gets easier to understand public policy now doesn't it.