When Americans were asked in 1993 about whether U.S. troops should be able to serve, even if they’re gay, a majority (55%) were opposed to the idea. About eight years later, in 2001, public opinion had already shifted a great deal — 62% of Americans supported gays serving openly in the Armed Forces, while 35% did not.

And now, as hearings on "Don't Ask, Don't Tell" are poised to begin on the Hill, public opinion on the issue is practically one-sided -- in a progressive direction.

Seventy-five percent of Americans in a new Washington Post-ABC News poll said gay people who are open about their sexual orientation should be allowed to serve in the U.S. military, up from 62 percent in early 2001 and 44 percent in 1993.

Majorities of Democrats, Republicans and independents alike now believe it is acceptable for openly gay people to serve in the U.S. armed forces. Shortly after he took office in 1993, Clinton faced strong resistance to his campaign pledge to lift the military’s ban on allowing gay people to enlist. At that time, 67 percent of Republicans and 75 percent of conservatives opposed the idea. A majority of independents, 56 percent, and 45 percent of Democrats also opposed changing the policy.

Today, Americans have become more supportive of allowing openly gay men and women to serve in the armed forces. Support from Republicans has doubled over the past 15 years, from 32 to 64 percent. More than eight in 10 Democrats and more than three-quarters of independents now support the idea, as did nearly two-thirds of self-described conservatives.

That’s really quite extraordinary. Get this: even 57% of evangelical Protestants support gays serving openly in the military.

On the one hand, it’s a very encouraging development. It’s hard to know what prompted the reversal, but I wouldn’t be surprised if it had something to do with the need for well-trained, physically-fit, patriotic Americans volunteering for duty during two wars, regardless of those Americans’ sexual orientation.

And on the other hand, we have John McCain and the Republican Party establishment.

The poll found that nearly two-thirds of Republicans support allowing gays to serve openly in the military. But on this, rank-and-file Republicans are way ahead of their leadership. The Bush White House, for example, continues to insist that “Don’t Ask, Don’t Tell” remains in place. And then, more importantly, there’s John McCain.

When the Servicemembers Legal Defense Network asked McCain to talk about his position on the issue, McCain responded by calling gay soldiers an “intolerable risk.”

In an April 16 letter to Servicemembers Legal Defense Network (SLDN), McCain says the law, passed in 1993, “unambiguously maintains that open homosexuality within the military services presents an intolerable risk to morale, cohesion and discipline.” Senator McCain goes on to incorrectly assert that the U.S. Supreme Court “has ruled that the military may constitutionally discharge a service member for overt homosexual behavior.” […]

“Most importantly, the national security of the United States, not to mention the lives of our men and women in uniform, are put at grave risk by policies detrimental to the good order and discipline which so distinguish America’s Armed Services.”

First, McCain cites a Supreme Court ruling that doesn’t exist. Strike one.

Second, McCain calls gays an “intolerable risk” to military morale, cohesion, and discipline. Really? According to a Zogby poll of active personnel conducted, 73% of military members say they are comfortable around lesbians and gays. For that matter, more than one in five U.S. troops already knows a gay person in their unit, including combat units. So where’s the “intolerable risk”? Strike two.

Third, McCain emphasizes “national security” as a rationalization for discrimination. In what way, exactly, does it improve our national security for, say, Bleu Copas, a decorated sergeant and Arabic language specialist who joined the Army after the 9/11 attacks, to be thrown out of the military for being gay, despite his role in helping translate intercepted messages from possible terrorists? Are we more or less safe with Copas as a civilian? Strike three.

There isn’t even a political upside — Americans overwhelmingly agree with Barack Obama on this, and have concluded that gays should be able to serve openly.

I’d remind McCain that the first U.S. Marine seriously wounded in Iraq was Staff Sgt. Eric Alva, who lost his leg when he stepped on a land mine. Because Alva is gay, McCain apparently thinks Sgt. Alva had no business joining the U.S. military. That somehow, his sacrifice was in vain because he shouldn’t have been allowed to wear a uniform in the first place.

Americans are, to our enormous credit, leaving McCain and his antiquated, discriminatory worldview behind. We’re a stronger country for it.