Put simply, we've learned a lot since 1787. What was for the Founders a kind of providential revelation—designing, from scratch, a written charter and democratic system at a time when the entire history of life on this planet contained scant examples of either—has been worked into science. More than 700 constitutions have been composed since World War II alone, and other countries have solved the very problems that cripple us today. It seems un-American to look abroad for ways to change our sacred text, but the world's nations copied us, so why not learn from them?

No Longer a Model

Supreme Court Justice Ruth Bader Ginsburg was pilloried when she told Egyptian revolutionaries last year that she "would not look to the U.S. Constitution, if I were drafting a constitution in the year 2012." But her sentiment is taken for granted by anyone who has actually tried to write a constitution since politicians stopped wearing powdered wigs. "Our Constitution really has been a steady force guiding us and has been perhaps the most stable in the world," says Louis Aucoin, who has helped draft constitutions in Cambodia, East Timor, Kosovo, Rwanda, and elsewhere while working with the U.N. and other groups. "But the disadvantage to the stability is that it's old, and there are things that more-modern constitutions address more clearly."

Almost nobody uses the U.S. Constitution as a model—not even Americans. When 24 military officers and civilians were given a single week to craft a constitution for occupied Japan in 1946, they turned to England. The Westminster-style parliament they installed in Tokyo, like its British forebear, has two houses. But unlike Congress, one is clearly more powerful than the other and can override the less powerful one during an impasse.

The story was largely the same in defeated Nazi Germany, and more recently in Iraq and Afghanistan, which all emerged from American occupation with constitutions that look little like the one Madison and the other framers wrote. They have the same democratic values, sure, but different ways of realizing them. According to researchers who analyzed all 729 constitutions adopted between 1946 and 2006, the U.S. Constitution is rarely used as a model. What's more, "the American example is being rejected to an even greater extent by America's allies than by the global community at large," write David Law of Washington University and Mila Versteeg of the University of Virginia.

That's a not a fluke. The American system was designed with plenty of checks and balances, but the Founders assumed the elites elected to Congress would sort things out. They didn't plan for the political parties that emerged almost immediately after ratification, and they certainly didn't plan for Ted Cruz. And factionalism isn't the only problem. Belgium, a country whose ethnic divisions make our partisan sparring look like a thumb war, was unable to form a governing coalition for 589 days in 2010 and 2011. Nevertheless, the government stayed open and fulfilled its duties almost without interruption, thanks to a smarter institutional arrangement.