Political endorsements matter in as much as they become a multi-day story. And Colin Powell's endorsement of Barack Obama had the potential to be a reliable two-day story for the Democrat, a plus, of course, given that there are just 16 days remaining in the contest. But Powell went several steps further than a simple endorsement, and in so doing he not only conveyed to Obama his valued seal of approval as one of the nation's most respected military and foreign policy minds, he picked apart John McCain's case for his candidacy and denounced the Republican nominee's approach to winning the presidential contest.

Here's how:

-- He affirmed the Obama campaign line that McCain has been erratic in his response to the nation's economic crisis.

Powell: "In the case of Mr. McCain, I found that he was a little unsure as to deal with the economic problems that we were having and almost every day there was a different approach to the problem. And that concerned me, sensing that he didn't have a complete grasp of the economic problems that we had."

-- He said the American people aren't interested in negative politics, and he questioned McCain's use of Bill Ayers and related robocalls.

Powell: "And I've also been disappointed, frankly, by some of the approaches that Senator McCain has taken recently, or his campaign ads, on issues that are not really central to the problems that the American people are worried about. This Bill Ayers situation that's been going on for weeks became something of a central point of the campaign. But Mr. McCain says that he's a washed-out terrorist. Well, then, why do we keep talking about him? And why do we have these robocalls going on around the country trying to suggest that, because of this very, very limited relationship that Senator Obama has had with Mr. Ayers, somehow, Mr. Obama is tainted. What they're trying to connect him to is some kind of terrorist feelings. And I think that's inappropriate. Now, I understand what politics is all about. I know how you can go after one another, and that's good. But I think this goes too far. And I think it has made the McCain campaign look a little narrow. It's not what the American people are looking for. And I look at these kinds of approaches to the campaign and they trouble me."

-- He criticized not just the suggestion by some Republicans that Obama is a Muslim but also the broader implication of using religion to divide.

Powell: "He is not a Muslim, he's a Christian. He's always been a Christian. But the really right answer is, what if he is? Is there something wrong with being a Muslim in this country? The answer's no, that's not America. Is there something wrong with some seven-year-old Muslim-American kid believing that he or she could be president? Yet, I have heard senior members of my own party drop the suggestion, 'He's a Muslim and he might be associated terrorists.' This is not the way we should be doing it in America."

-- He criticized McCain's pick of Sarah Palin and praised Obama's selection of Joe Biden as deliberate.

Powell: "And I was also concerned at the selection of Governor Palin. She's a very distinguished woman, and she's to be admired; but at the same time, now that we have had a chance to watch her for some seven weeks, I don't believe she's ready to be president of the United States, which is the job of the vice president. And so that raised some question in my mind as to the judgment that Senator McCain made. On the Obama side, I watched Mr. Obama and I watched him during this seven-week period. And he displayed a steadiness, an intellectual curiosity, a depth of knowledge and an approach to looking at problems like this and picking a vice president that, I think, is ready to be president on day one."

-- He concludes that Obama is indeed a "transformational" figure and calls for a generational change in leadership, sanctioning the Democrat's experience and credentials.

Powell: "So, when I look at all of this and I think back to my Army career, we've got two individuals, either one of them could be a good president. But which is the president that we need now? Which is the individual that serves the needs of the nation for the next period of time? And I come to the conclusion that because of his ability to inspire, because of the inclusive nature of his campaign, because he is reaching out all across America, because of who he is and his rhetorical abilities--and we have to take that into account--as well as his substance--he has both style and substance--he has met the standard of being a successful president, being an exceptional president. I think he is a transformational figure. He is a new generation coming into the world-- onto the world stage, onto the American stage, and for that reason I'll be voting for Senator Barack Obama."

Powell discounts the chief arguments McCain has made for his candidacy and against Obama's. He said he won't stump for the Democratic nominee, but he doesn't have to. His words will resonate -- and likely show up in ads running in battleground states -- until Nov. 4 and could go far in helping Obama woo moderate voters in the waning days of the race.

There is nothing McCain can say or do to diminish the power of Powell's words without knocking the former chairman of the Joint Chiefs. And that would only prove Powell's point, wouldn't it?

(JENNIFER SKALKA)