The reason the polls got it wrong? Polling, then in its infancy, relied, like today, on telephone interviews. However, in 1948 telephone service was still expensive and a luxury: most typical homes did not have phone service. Polling services did not account for this upper-income bias, and as a result, their surveys were comprised disproportionately of upper-income citizens, who tend to be identified with and vote Republican. Those tens of millions of Americans who didn't have phones voted for Truman, granting him the victory.

Moreover, pundits and other political watchers were so confident that Dewey would win, The Chicago Tribune printed an advance copy of the paper, before the polls closed that read: "Dewey Defeats Truman."

The picture of President Truman holding a copy of the "Dewey Defeats Truman" photo, smiling, after election results demonstrated that he, not Dewey, had won, is considered to be one of the biggest gaffs in American journalism (and polling) history.

Since that polling debacle in 1948, survey research organizations having instituted many checks to ensure that their polls are random and representative of the U.S. electorate.

Political/Economic Analysis: Early voting data suggests the 2008 U.S. presidential election could record the highest percentage turnout of registered voters since the 1960 presidential election.

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Financial Editor Joseph Lazzaro is writing a book on the U.S. presidency and the U.S. economy.