On Sunday, General Colin Powell, the former secretary of state under George W. Bush and longtime Republican, endorsed Senator Barack Obama for president.

On Meet the Press, host Tom Brokaw asked Powell what he thought of the two candidates, and whether he was prepared to publicly endorse one of them right then. Powell didn't hesitate, and offered his answer only after a thorough explanation.

He described his 25-year association with Senator McCain, and his two years of knowing Senator Obama, noting that he had some misgivings about both candidates in the early going. He said he regrets that the Republican party has moved so far to the right in recent years, and that he fears McCain will only continue that trend. He then said that he told Obama that he would need to prove he has the necessary experience to win people's confidence during difficult times.

The "final exam," as Powell called it, was the financial crisis and how each candidate reacted on the national stage. He criticized McCain for lacking a clear agenda, and for routinely changing his approach in how he'd deal with it. By the same token, he praised Obama for his steadiness and his intellectual engagement with the problem.

He also lauded Senator Biden, saying he believes that Obama's running mate could easily jump in and serve as president if necessary.

He continued to praise Obama and criticize McCain for everything from his tactics to his policies, and mentioned that he would be "have difficulty" with two more conservative appointments to the Supreme Court.

Perhaps the boldest thing Powell said in his appearance was that he is not only "troubled" by the criticisms that Obama is a Muslim, because he isn't, but that people in America consider that a problem.

"The really right answer is, 'So what if he is?'" Powell said. "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 7-year-old Muslim American kid believing he can be president someday?"

Powell said he has even heard senior members of his own party make the same argument against Obama, and said, definitively, "This is not the way we should be doing it in America."

This served as a long but engaging preamble for what may be the most important -- and in some ways, unexpected -- endorsement Barack Obama will have received during his campaign.

Here is General Powell's eloquent, unequivocal, inspiring explanation for why he will be voting for Obama, in its entirety.