On February 2, 1948, President Harry Truman declared in a special civil rights message to Congress that he "had instructed the Secretary of Defense to take steps to have the remaining instances of discrimination in the armed services eliminated as rapidly as possible." On July 26, 1948, Truman issued Executive Order 9981 instituting the new policy that "there shall be equality of treatment and opportunity for all persons in the armed services without regard to race, color, religion, or national origin." Now, almost exactly 62 years to the day after Harry Truman demanded the integration of the U.S. military, Colin Powell - the most potent symbol of the success of that transformation - announced gay and lesbian Americans deserve the same opportunity to serve their nation.
One day after Joint Chiefs Chairman Michael Mullen embarrassed John McCain and other fear mongering Republicans, the man who doomed the 1993 effort to end discrimination in the armed forces reversed course. Mullen's predecessor Powell announced:

"In the almost 17 years since the 'don't ask, don't tell' legislation was passed, attitudes and circumstances have changed. I fully support the new approach presented to the Senate Armed Services Committee this week by Secretary of Defense Gates and Admiral Mullen."

The significance of Colin Powell's belated change of heart can't be understated.
In 1966, Professor Charles Moskos, among the nation's foremost authorities on racial integration in the U.S. military, documented the rapid progress since Truman's order, progress which he suggested spoke well not just of the armed forces as an institution but for the future prospect of American society overall:

By the middle 1950's this policy was an accomplished fact...Within a remarkably short period the makeup of a major American institution underwent a far-reaching transformation.

Thirty one years later in 1997, Moskos told David Gergen that the military was at the forefront of racial progress in the United States, and not merely because Colin Powell had risen to the rank of Joint Chiefs Chairman:

"It's the only institution in American society where white people are routinely bossed around by blacks and where black leadership is very, very evident and well regarded. I mean, obviously, Colin Powell comes to mind, but I might add that 9 percent of all army generals today are black, as are approximately 1/3 of all first sergeants and sergeant majors. It's not utopia by any means. There are problems in the military. It's got racist in it, but in terms of any other institution one wants to compare it with, black leadership is far and away superior."

Sadly for both the nation and his own reputation, Charles Moskos could not overcome his own biases when it came to openly gay Americans serving in the U.S. military. Before his death in 2008, Moskos authored the DADT policy in 1993, arguing "To me, the issue comes down to privacy. Prudes have rights too."
Now, with President Obama, Secretary Gates and Chairman Mullen pushing for the repeal of the DADT policy which shames the United States even as it undermines its national security, many of the same specious arguments and none-too-subtle code words are once again being deployed.
John McCain, for example, declared himself "disappointed" in the testimony from Gates and Mullen, arguing "At this moment of immense hardship for our armed services, we should not be seeking to overturn the 'don't ask, don't tell' policy." His Republican colleague Saxby Chambliss (R-GA) fretted that "the presence in the armed forces of persons who demonstrate a propensity or intent to engage in homosexual acts would very likely create an unacceptable risk to those high standards" of morale, good order and discipline, and unit cohesion. And while Chambliss worried about an explosion of "alcohol use, adultery, fraternization, and body art" in the U.S. military, fellow Republican Duncan Hunter was concerned about something else: hermaphrodites:

"I think it's bad for the cohesiveness and the unity in the military especially those that are in close combat, close quarters in country right now, it's not the time to do it. I think the military is not civilian and I think the folks that have been in the military in very close situations with each other, there has to be a special bond there and I think that bond is broken, if you open up the military to transgenders, to hermaphrodites to gays and lesbians."

Of course, the United States has been here before. As the Center for American Progress documented last year, 62 years ago the target color of bigotry was black and not rainbow. And yet Harry Truman pressed ahead in a much less friendly political environment, despite the same hatemongering from both parties and even Army Chief of Staff General Omar Bradley:

Truman's effort to desegregate the armed forces also faced strong opposition from members of both parties in Congress. Sen. Richard Russell (D-GA), the then-ranking minority member of the Senate Armed Services Committee, claimed that desegregation would lead to a weaker force because it would be "sure to increase the number of men who [would] be disabled through communicable diseases and the crime rate among servicemen [would] soar." Senate Majority Leader Robert Taft (R-OH) called Truman's executive order a cheap political ploy. Some of Obama's opponents in Congress will likely employ similar arguments against DADT, and the president must be prepared to display the same strong leadership Truman exhibited.
President Truman also faced significant opposition from the country. Only 13 percent of Americans supported "having negro and white troops throughout the U.S. armed services live and work together" when he issued his executive order to end segregation in the armed forces. Obama's potential support is much greater. A 2009 Washington Post-ABC News poll from July 2008 showed that 75 percent of Americans now believe that gay people should be allowed to serve openly.

Mercifully, much has changed in the United States. In the 1960's, conservative southern Democrats bolted the party for the open arms of the GOP in order to perpetuate the final vestiges of the Jin Crow system. And since then, Colin Powell didn't just reach the pinnacle of American military leadership. Unlike his champion Charles Moskos, he saw the light.
UPDATE: As ThinkProgress and TPM among others have noted, John McCain now has some serious explaining to do. For years, he has cited Colin Powell to back his refusal to oppose DADT. This includes his June 2009 claim that "The reason why I supported the policy to start with is because General Colin Powell, who was then the Chairman of the Joint Chiefs of Staff, is the one that strongly recommended we adopt this policy in the Clinton administration," adding, "I have not heard General Powell or any of the other military leaders reverse their position."