There was no legislation segregating the military that Truman’s Executive Order 9981 (July 26, 1948) had to supersede. Moreover, Congress specifically defeated legislative efforts toward segregation. In May 1948, Sen. Richard B. Russell (D-GA) attached an amendment to the Selective Services bill then being debated in Congress. The Russell amendment would have granted draftees and new inductees an opportunity to choose whether or not they wanted to serve in segregated military units. Russell’s amendment was defeated in committee. In June 1950 when the Selective Services Law came up for renewal, Russell tried again to attach his segregation amendment, and again Congress defeated it.

At the end of June 1950, the Korean War broke out. The U.S. Army had accomplished little desegregation in peacetime and sent the segregated Eighth Army to defend South Korea. Most black soldiers served in segregated support units in the rear. The remainder served in segregated combat units, most notably the 24th Infantry Regiment. The first months of the Korean War were some of the most disastrous in U.S. military history. The North Korean People’s Army nearly drove the American-led United Nations forces off the Korean peninsula. Faced with staggering losses in white units, commanders on the ground began accepting black replacements, thus integrating their units. The practice occurred all over the Korean battle lines and proved that integrated combat units could perform under fire. The Army high command took notice. On July 26, 1951, the US Army formally announced its plans to desegregate, exactly three years after Truman issued Executive Order 9981.

(You’ll sometimes find rabid Republicans who insist that Truman didn’t really desegregate the military, and that Eisenhower should get the credit because he was president when the military actually achieved complete racial integration.)

As you can see from this capsule history, an Executive Order given to a reluctant military, even where Congress’s wishes are not to the contrary, can take a long time and a crisis situation to implement. If Obama issued an EO specifically as a runaround on DADT, there will be a lot more resistance in the military than if it happens with a Congressional repeal of DADT.

An EO freezing discharges until repeal would not only be ENTIRELY legal under 10 USC 12305 but end what Obama himself referred to as weakening national security.

If the core, motivated Repugs [versus the 59% of Repug voters who support lifting the ban] didn’t hate gays so much that’s ANOTHER thing they’d be attacking him for: aiding and abetting the terrorists by continuing to fire Arab linguists, etc., etc.