The match-up would pit the 71-year-old McCain, who if elected would become the oldest president ever, against the 46-year-old Obama, who would be one of the youngest.
We're starting to get a glimpse of what this race would be all about. By seizing on the mantle of change, Obama has drawn record numbers of young voters to the polls who see him a something of a rock star.
And, after their respective victories in the Potomac Primaries on Tuesday, both men seemed to set their sights on each other. McCain called hope a "powerful thing", saying he's seen men's hopes tested in hard and cruel ways.
He then went on to contrast his POW experience with Obama's speeches, adding: "To encourage a country with only rhetoric rather than sound and proven ideas that trust in the strength and courage of free people is not a promise of hope. It is a platitude." Those would be classified as "fightin' words."
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