During their time in the Senate, John McCain has voted in a free-trade direction on 88 percent of major votes affecting barriers to trade, Barack Obama only 36 percent of the time. But on trade with the pathetic, socialist island of Cuba, the two presumptive presidential nominees swap places.

In a speech yesterday, McCain accused Obama of changing his position on the U.S. government’s almost 50-year-old embargo against Cuba. “Now Senator Obama has shifted positions and says he only favors easing the embargo, not lifting,” Mr. McCain said, according to a story in this morning’s New York Times. “He also wants to sit down unconditionally for a presidential meeting with Raúl Castro. These steps would send the worst possible signal to Cuba’s dictators—there is no need to undertake fundamental reforms, they can simply wait for a unilateral change in U.S. policy.”

Cuba is one of the few trade-related issues where Democrats generally come down on the right side and Republicans on the wrong side, and the two presidential front-runners are true to type.

According to the Cato Institute’s “Free Trade, Free Markets” web feature that tracks congressional votes on trade, Sen. McCain voted in 2003 against ending the ban on Americans traveling to Cuba. In 2005, Sen. Obama voted to defund enforcement of the ban. In their public statements, McCain has supported the comprehensive embargo in place since 1960, while Obama has questioned its usefulness.

The politics behind the embargo are quite straightforward. Florida is a swing state that is home to half a million politically active Cubans who rightly detest the communist regime in Havana. Many of them wrongly see the embargo as a test of America’s resolve to bring an end to the regime. But the embargo’s lack of substance is also equally straightforward. After almost half a century, the embargo has failed to prompt the Cuban government to undertake anything remotely resembling “fundamental reforms.” It has made the Cuban people a bit poorer, while not making them one bit freer.

For a comprehensive argument against the embargo, check out the text of a speech I gave in 2005 at the James A. Baker III Institute at Rice University in Houston. The only thing I would consider changing is the title, which was, “Four Decades of Failure: The U.S. Embargo against Cuba.” My new title would be, “Almost Five Decades of Failure.”