I'm in agreement with Ernest with regard to DoE.
Homeland Security is something I can easily see under Defense. But I can just as easily see it under AG. Yet again, I can see it being something warranting division from both, perhaps an "Interior" heading...which brings up this:
Ernest's inclusions under State don't make sense to me yet. (everything else is a bullseye, imo) I see the function of Diplomacy (and its overwhelming complexities all by itself) far departed from FCC, Interior, DoT, and the GSA. If it were a matter of keeping the Secretary of State busy...oh boy howdy am I gonna keep him busy... >
I do think USAID is again worth an explicit mention for State, as it's easily arguable under Commerce but its agenda is more than of soley economic strength for US interests, but rather our diplomatic interests that aren't necessarilly going to show a good balance sheet anytime soon--yet contributing greatly to our security strategems.
Interior, DoT, GSA, maybe NASA for the sake of tradition:
Whatdya say we give 'em to the VP! These aren't the sexy jobs, but they're important--and gives the VP a chance to contribute to the Administration instead of waiting around for...well...you know. This can be an informal accomodation---these policies officially resting on the President's direct authority--so no legislation or amending has to occur, don't you think?
Plus, this accomodation may include 'Homeland Secuirty' for the VP as well--to further divide the power to police...and share the secuirty gaming to boot.