Now that the most prominent military figure of our era - also a lifelong Republican, also George W. Bush's first Secretary of State, also a friend of John McCain's for 25 years - has publicly endorsed Barack Obama, it will be fascinating to behold the McCain surrogates and under-the-radar whisperers as they try to spin this one away. Maybe we'll get variations of these:

1. Colin Powell has no credibility anymore, ever since he lied at the United Nations.

2. Colin Powell, a longtime moderate and supporter of abortion, has never been a real Republican anyway.

3. Colin Powell lives in McLean, Virginia, and we all know that Northern Virginia is not the "real" Virginia.

4. ACORN put him up to it.

5. Black people always stick together.

6. We've still got Joe the Plumber.

But seriously folks...when I saw the Powell endorsement this morning, on Meet the Press, I was reminded of something that Indiana Republican Sen. Dick Lugar said about Powell way back in 1995, when it appeared that the retired general might seek the '96 GOP presidential nomination. Lugar said that if Powell ran, it would be akin to "the displacement of water that comes if you drop a skyscraper into the harbor." Obviously, no endorsement can be considered that weighty - but, as endorsements go, Powell's formal vetting of Obama ("the president that we need now") is potentially quite consequential. The symbolism alone makes it so.

First, Powell is one of the most popular public figures in America - viewed favorably by 76 percent of voters, according to an August poll by Fox News, so his opinion matters. Second, his military and foreign views command wide respect; indeed, the "Powell doctrine" (America should go to war only when it can fight with overwhelming force, with strong popular support, and with an exit strategy) is viewed as the antithesis of the Bush-Cheney cowboy credo. Third, Powell is particularly popular among military retirees - who also happen to be particularly populous in three red states where Obama is strongly competitive (Florida, Virginia, North Carolina.

Powell essentially signaled that Obama, despite his inexperience, trumps McCain on judgment. He signaled that Obama has a better take on how America should conduct its foreign policy, and that McCain's approach is too closely tied to the Bush administration (despite McCain's insistence these days that he is not Bush redux). Powell also signaled that, as a career military man, he is nevertheless more comfortable with Obama at the helm of national security policy - because McCain would "continue, basically, the policies we have been following in recent years."

Powell did not personally assail McCain today, except by implication. By lauding Obama's "steadiness...intellectual curiousity...depth of knowledge...intellectual vigor," he strongly suggested that McCain lacks those crucial attributes. But he minced no words while talking about the McCain campaign, and the Republican party itself. He said that, while Obama is busy reaching out, the GOP and the McCain campaign have become "narrower and narrower." He said that Obama is "crossing ethnic lines, racial lines, generational lines. He's thinking about, 'all villages have values, all towns have values' - not just 'small towns have values'."

That latter reference was one of several swipes at Sarah Palin, whom he deems unqualified for higher office - and whose presence on the ticket "raised some question, in my mind, as to the judgment that Sen. McCain made." He twice assailed the GOP's obsession with ex-'60s bomber Bill Ayres ("why do we have these robocalls going out around the country?...it's demagoguery"), and he denounced the lies being spread "by members of the party" about how Obama is supposedly a Muslim. All told, Powell said that "we've got to stop polarizing ourselves in this way."

Moreover, he contended that the party's "further rightward shift" - which is best epitomized by McCain's choice of Palin - could adversely impact the future of American jurisprudence. Or, as he put it, "I would have difficulty with two more conservative appointees to the Supreme Court, but that's what we'd be looking at in a McCain administration." Powell, the longtime defender of abortion rights, appeared to be aiming that message at suburban white women, notably the moderates and Republicans who might still be on the fence, and who perhaps need to be reminded about the perilous status of Roe v. Wade.

This endorsement will dominate the news cycle for a day or two, and there are precious few days remaining. I instinctively recoil from uttering certitudes, so I won't make the case that the Powell validation constitutes game, set, and match for Obama. On the other hand, McCain has virtually no spin options on this one. All he can do is go forth in denial and again tell his audiences, "My friends, we've got them where we want them."