Former Secretary of State Colin Powell has come off the fence and endorsed Barack Obama for president.

He said he had watched both Obama and his Republican opponent, Sen. John McCain of Arizona, for many months and thought “either one of them would be a good president.”

But he said McCain’s choices in the last few weeks — especially his selection of Gov. Sarah Palin of Alaska as his vice presidential running mate — had raised questions in his mind about McCain’s judgment.

“I don’t believe [Palin] is ready to be president of the United States,” Powell said flatly. By contrast, Obama’s running mate, Sen. Joe Biden of Delaware, “is ready to be president on day one.”

Anyone who still thinks highly of a vice presidential pick that inspired this is... well, is probably a poster on Free Republic. For a long stretch of the 1990s, it was assumed that Powell would become the first black president. That was the only path anyone saw for a black president: he had to be a military veteran, a Republican, a moderate completely unconnected to the likes of Jesse Jackson. As Derrick Z. Jackson wrote in the Boston Globe in 1995, after Powell passed on a presidential bid:

White America has to find another Great Black Hope. Powell said yesterday that he will not run for president. For many African-Americans, including myself, it is a bit of a drag that he is not running. It takes tremendous pressure off President Clinton to take our vote seriously. Many of us would love to see the Democrats squirm after years of treating our loyal votes like Cinderella after midnight.

Well, white America found another one. Politically Powell disinfects Obama from the Wright and Ayers and other assorted stains he picked up this year. You might get an e-mail claiming Obama is a terrorist, but if Colin Powell says he isn't, well, that e-mail is probably a hoax. If all Powell does is knock back McCain for a day or two, then, as Mark Halperin points out, that's 20 to 25 percent of the remaining news cycles before election day that he's lost. Expect them to spin something like how they'd rather have Joe the Plumber's endorsement than that of Colin Powell. Spin like that will turn Joe from a political asset to the latest McCain gimmick.

The Powell endorsement shouldn't be all good for Obama. Powell's tenure at State was, in retrospect, a disaster. Obama's rise began when he gave an anti-Iraq War speech. Powell's career started spiralling when he made the case for war at the United Nations. But Powell is still a folk hero because of the narrative that's been spun since them. You get a good example of it in Oliver Stone's W., which I saw last night, and which portrays Powell as a fallen saint who literally pounds a table ("LET ME FINISH!") making an argument against invading Iraq. The country sees Powell not as a patsy, but as a guy who would, after all, have made a better president than Bush.