Just to put Colin Powell's endorsement of Barack Obama over John McCain into a bit of perspective, here are a few past comments by McCain praising Powell to the hilt. Also, keep in mind that McCain considered Powell as his running mate this year. (bolding added by me for emphasis in all the quotes)
*In the New York Times, McCain referred to Colin Powell as "a man who I admire as much as any man in the world, person in the world."
*On November 8, 1995, John McCain had the following to say about Powell's decision not to run for president: "I am saddened to learn that Colin Powell has decided against seeking the Republican nomination for President in 1996." McCain continued:
...His is a sterling record of service that none of his detractors ever considered rendering this nation, and they should be ashamed of themselves for attempting to dissuade a Powell candidacy by attacking his good name. I would like to think that there is more room in the Republican Party for Colin Powell than there is for those who substitute character assassination for political debate.I sincerely hope that General Powell will still consider playing an important role in the Republican Party and in the affairs of this nation. I am quite confident he would have a bright future in the party and in government. He is a man of proven ability, of abiding patriotism, and superior character. I would be as proud to call Colin Powell a Republican as I have always been to call him my friend.
*On November 15, 2004, John McCain issued the following statement regarding Colin Powell's resignation as Secretary of State.
In announcing his resignation, Secretary of State Colin Powell has prompted all Americans to consider his great service to our country. When he took the helm at the State Department nearly four years ago, I was confident that Secretary Powell would lead with honor and distinction. I have not been disappointed.Secretary Powell has been masterful at representing America abroad, and in tackling problems large and small. He has shown great skill and dedication in leading the men and women of the State Department, as evidenced by their fierce loyalty and praise. He understands that American interests and American values must coincide in our foreign policy.
I have had the honor of knowing Secretary Powell for many years, and I am privileged to call him a friend. As he reenters private life, I wish him every possible success. He is a true American hero.
*On July 10, 2006, John McCain said the following, in the context of arguing for comprehensive immigration reform.
"Some of our most decorated and famous serviceman, including former Secretary of State Colin Powell, are first generation Americans or immigrants themselves."