The Democratic Party's two remaining candidates have become so cordial toward one another that you could easily believe there are few substantive differences between them. At last Thursday's debate, Barack Obama and Hillary Clinton heartily agreed on most issues and added that they were having a wonderful time chatting with one another. The Republican race, by contrast, is bubbling over with tensions and personal animosities. Watch any encounter between John McCain and Mitt Romney and you can almost see the smoke steaming out of each one's ears.

This Democratic amity is not just about making up. The party is far more united than in the past. And yet there are important distinctions between Obama and Clinton—and not simply in the broad, almost gassy talk of inspiration versus experience. They come to today's challenges from very different places.

Consider Cuba policy. Almost anyone who is being honest will acknowledge that America's approach toward Cuba is brain dead. No one even remembers why we've imposed a total embargo on the country. A policy that was put into place at the height of the cold war, when fears of Soviet missiles and communist penetration were at their peak, has been maintained even though the threat that prompted it has collapsed. What exactly are we afraid this moth-eaten island will do to America today?

Our policy has the additional burden of having failed, by any measure. We've been trying to force regime change in Cuba for 45 years. Instead Fidel Castro is now the longest-lived head of government in the world. Every tightening of the Cuban embargo has resulted in further repression and isolation. And yet the only changes George W. Bush has made to our Cuba policy have been to impose more restrictions on travel and trade, a cruel and futile doubling down on a bad bet.

Obama has advocated easing the Bush-imposed ban on Cuban-Americans visiting the island and sending money to their relatives. He makes a broader case for a new Cuba policy, arguing that capitalism, trade and travel will help break the regime's stranglehold on the country and help open things up.

Clinton immediately disagreed, firmly supporting the current policy. This places her in the strange position of arguing, in effect, that her husband's Cuba policy was not hard-line enough. But this is really not the best way to understand Clinton's position. In all probability, she actually agrees with Obama's stand. She is just calculating that it would anger Cuban-Americans in Florida and New Jersey.