Actually, as mentioned earlier in this thread (IIRC), DADT was legislation. Before DADT, the President could have simply signed an executive order allowing gays to openly serve*, but now that it has been legislated, the President cannot simply modify at his own discretion existing law.
Actually, no, he could not, as the Congress was happy to point out to President Clinton at the time, the law at the time being "it is illegal to be a homosexual and serve in the Armed Forces." (Paraphrase of the regs at the time).
The rules by which the military are manned and funded come from Congress, not the White House. This was brought up around the time of testimony by ADM Jeremiah and General Powell by Senators from both parties. I recall watching as much of the testimony as I could at the time, CSPAN had some of it.
The Commander in Chief bit and executive responsiblity are not one and the same as the authority and responsiblity for writing all of the rules and laws.
From Article 8 of the Constitution, in support of that point being made back then, and the Powers of Congress:
To declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water;
To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years;
To provide and maintain a Navy;
To make Rules for the Government and Regulation of the land and naval Forces;
To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;
To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress;
The balance of powers is a potential check on any executive order, which I think is why President Clinton didn't resort to that.
Like him or not, he isn't stupid. I think he saw the DADT as a step forward, which it was, but it certainly left a lot of loose ends hanging, and left a lot of people unsatisfied.
DR