The past and future of the Panama Canal weigh heavily on Martín Torrijos, like a freighter inching through a lock. It was Torrijos' father, the late Panamanian strongman Brigadier General Omar Torrijos, who persuaded the U.S. to sign a 1977 treaty handing over the canal to Panama, which it did six years ago. Now Torrijos, 43, who was democratically elected President of Panama in 2004, is stumping to persuade his countrymen to undertake a more than $5 billion expansion of the 50-mile-long waterway that bisects the isthmus.
The project--which voters look set to approve in an Oct. 22 referendum--may not compare with...