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Fred W. Smith, Founder and CEO, FedEx
Smith, an ex-Marine, runs a global enterprise of staggering logistical complexity. And McCain has said he'd make a good Defense Secretary.

But Smith doesn't always back McCain, parting ways recently on a proposal to temporarily lift the federal gas tax.

Said Smith: "I'm an ardent supporter of Senator McCain, but I don't agree with him on everything.... Will it have any major effect on the energy crisis? The answer to that is no."

NEXT: Meg Whitman Former CEO, eBay
Last updated July 28 2008: 5:20 PM ET
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