While both Senators John McCain and Barack Obama have courted the former chief of staff, and Powell described having had extensive discussions with both candidates, he said he is currently weighing the decision between them as a decision of an individual decision.
More than anything, though, he said he was concerned about America's capacity to lead in a world which has witnessed its largest expansion of wealth in history, and faces myriad of related challenges.
Interviewed by Aspen Institute CEO Walter Isaacson along with former Georgia Sen. Sam Nunn, Powell said he would vote for the person he sees has having the right vision for America, the right competence and the right team, but also the person who can best add "the right spark to the American presidency, because the rest of the world is looking for a spark."
Powell said he was concerned about America's fallen image in the world, though he believes that is still recoverable because people believe in this country as a land of hope and of dreams and of opportunity.
The next president could restore that faith, making a concerted effort.
"Both of these candidates are capable of that," he said.
Asked by Isaacson to evaluate the presidential candidates, Powell said he he has had "long comprehensive" discussions with Obama, and that he has been good friends with John McCain, who he said should be respected as a true war hero.
On the eve of the Independence Day holiday, Powell said both candidates were totally dedicated to the welfare of the country and it was "a disservice to July 4," to debate who's the more patriotic between them.
McCain will be challenged by his close relationship with the Bush administration and by the fact, Powell said, that he has become leader of a party in disarray.
Obama is clearly charismatic, and may not have as much experience, but would have to demonstrate to America that he's got enough experience.
He said he'd come to a decision "in due course".
Powell and Nunn had engaged in a wide ranging discussion with Isaacson of Iraq, Afghanistan, Gays in the military, and other issues.
Powell noted the U.S. had managed low-level diplomatic contacts with Iran early in the Bush administration, and said of the Administration's refusal to talk now, "I don't think you can have a dialog with somebody when you put a precondition out there that asks the other party to give you what you want before you start talking."
Asked if that didn't sound like he was on the Obama side, the former general quickly retorted "I'm on the Colin Powell side."
He added it appeared centrifuges were spinning in Iran, and Europe and the United States may need to face the reality we don't have the diplomatic tools to prevent Iran from creating weapons grade uranium.
Nunn warned the world may be on the verge of an explosion of enrichment around the globe, and he proposed the only solution may be if every enrichment facility, including ours, comes under international inspections, including cameras and other technical means.
On Iran and Afghanistan, Powell acknowledged Isaacson's point that as the situation in Afghanistan deteriorates, it may have seemed more prudent to have continued to focus on Afghanistan rather than rushing into Iraq. "One can make that argument," Powell said, though he noted Afghanistan was thought to have been "under control" at the time.
At one point, Isaacson asked Sam Nunn whether he might consider the vice presidency under Obama, and Nunn responded he considered it a great honor to be mentioned in that regard, but did not expect to receive an offer, adding that the team around the president is very important.
"Right, Colin?" he asked.
"Yes," replied Powell.