03/27/2012 10:15 am ET Updated May 27, 2012

Does Good Business Make Bad Presidents?

Among the current crop of candidates for president, several have tried to sell their business experience as relevant to their future success in leading the federal government. Let's look at the best and worst presidents in light of their earlier careers.

All opinions are valid, but not all are valuable. The votes of presidential historians should count more than public opinion polls. C-SPAN conducted their Survey of Presidential Leadership among presidential historians over a 10-year period. The consensus was that the best presidents were Abraham Lincoln (postmaster), George Washington (surveyor) and Teddy Roosevelt (soldier). Basically, scholarly opinion breaks down to Mount Rushmore.

And among the worst? Warren Harding (business man), Andrew Johnson (business man) and James Buchanan (professional politician).

It's no surprise that the historians' pick for both the best (Lincoln) and the worst (Buchanan) presidents were also lawyers. It is the most common early career of presidents. Understanding law, building a solid case and mastering persuasive speaking are necessary attributes for any politician. On the other hand, lawyers have a well-deserved reputation for moral ambiguity, which can destroy a president surrounded by fiercely competitive special interests.

But why have so few presidents, and successful politicians in general, been businessmen? The answer lies in the stark and significant differences between running a government and running a business. The public understands this on a visceral level and election results tend to reflect that.

Businesses are run as an autocracy, whereas government in a democracy requires consensus. The economy of the federal government dwarfs any company's balance sheet, regardless of how large the business may be. The government has over two million employees -- most of whom do not answer to the president -- with Congress and the Courts empowered to act independently, often against the president's wishes. A president obviously cannot fire Congress for poor performance. The participation of people who would benefit when he fails is often necessary to implement his agenda. In contrast, any Fortune 100 chief executive should have a great deal more freedom in running her comparatively little enterprise. With near absolute control over her employees and taking home many hundred times the pay of an average worker, the modern CEO is much closer to a dictator than a democratic leader. Dictators, of either the business or political variety, generally don't make good presidents.

Corporate successes do not necessarily lend themselves to successful political leadership because the government and private enterprise have entirely different missions. Profitability is the main focus of a successful business leader. A business can, and should, restructure itself to get rid of unproductive workers and outsource its production to increase profits. The ravages of closed factories, long unemployment lines, foreclosed houses and broken homes are not stains on the record of a business executive. Nor should they be when the primary objective of a business is measured by the financial returns to its shareholders.

But the prosperity of a nation, and the focus of a president, means much more than the financial interest of a particular group. History rightly measures presidential success by the broad improvement in living standards, national security and social justice.

A business leader's key to success is the ability to select the best offered by society, whether it's personnel or opportunity, while rejecting the rest. A successful president, on the other hand, must lift the entire population; he must provide opportunities for the disadvantaged and the unskilled without dragging down the whole nation. A businessman thinks about moving his company to another country with a better-trained work force; a president must consider how to pay for retraining and investments in education. A businessman can improve his cash flow by shutting down unprofitable operations; a president cannot outsource his army even in a more peaceful time.

Empathy and persuasiveness are essential qualities of a successful president. Bill Clinton's famous uttering, "I feel your pain," in its sincere manifestation is the drive to lift the disaffected, the hard-pressed constituencies and, therefore, the wealth of a nation. This quality of empathy plays a part in many aspects of a presidency. Raymond Wolters, Professor of History at the University of Delaware, spoke about this quality in responding to a Wall Street Journal survey in 2000. He said that great presidents shared one thing in common: "They lifted the spirit of the nation." In a time of crisis, a president can secure his role in history by inspiring the country "to pay any price, to bear any burden" and find more fertile ground for all its people -- rich and poor, capable and unproductive.

With profitability as her singular mandate, a business leader needs neither empathy nor persuasiveness to succeed. Cold, hard cash is not motivated by empathy. And persuasion may not be necessary when the job comes with the power to issue pink slips. It is not surprising, then, that history tends to judge businessmen turned U.S. presidents poorly.

Will Romney, should he prevail this November, be the exception?