USCG to DoD?

My Senator has a proposal:

Freshman Sen. Rand Paul (R-Ky.) suggests trimming $500 billion from the federal budget this year (Fiscal Year 2011). Among the new senator's suggestions for getting the numbers down is to cut the DHS budget by 43%, according to a watchdog group, the Committee for a Responsible Federal Budget.

Paul proposes moving the Coast Guard - an armed, uniformed service - into DOD with all the other armed services. The Coast Guard would take its funding along with it to the Defense Department.

A summary explaining Paul's bill, which is labeled the “Cut Federal Spending Act of 2011,” states that the transfer from DHS “'will promote uniformity, administrative savings, and reduce duplicative functions.”

Is there any sense to this? I suspect that there might be some savings, but I can't imagine it would be all that large. Moreover, the act of shifting the USCG to DoD would probably incur a substantial one year cost, which wouldn't matter so much except that this is a plan to cut $500 billion in a year.

And another problem:

The way Paul and his advisers see it, the Coast Guard is practically a part of the DOD already because by law it operates under the authority of the Navy in time of war or when the president so directs. Coast Guard units are currently working with the Navy in the waters off Iraq as well as in anti-piracy operations near the Horn of Africa.

But Paul's folks seem to have forgotten, or ignored, the fact that the Coast Guard also has civilian law enforcement authority and is the only armed service exempt from the restrictions of the 1878 Posse Comitatus law that bars federal troops from enforcing civilian laws on U.S. soil (except in very limited situations like armed insurrection.)

Because of that law enforcement exemption, the Coast Guard's mission has been repeatedly expanded - especially since 9/11 - to include drug and illegal migrant interdiction, port security, vessel safety inspection and intruder interdiction in the airspace over Washington, D.C.

Coast Guard advocates also note the entire Coast Guard is never made a part of the Navy in wartime, just designated units, vessels and personnel. While Paul's plan to move the Coast Guard is considered highly unlikely to pass, it does raise the question of what would happen to the Coast Guard's role as the enforcer of U.S. maritime safety and security laws if it became just another one of the armed services.

The Posse Comitatus objection is legitimate, but surmountable through legislative action. I suspect that any modification that might weaken Posse Comitatus would worry Senator Paul, however. On the final point I'm not sure I understand the objection; the USCG is not a non-governmental organization, and doesn't belong to the UN. Why it should matter whether the USCG is part of DoD or DHS while enforcing US maritime safety and security laws isn't 100% clear to me.