Today, Gail Collins tackles Herman Cain. After examining his personal history and electoral strategy, she stumbles upon this:

For instance, on the matter of immigration, Cain says that he thinks it would be a great idea to build an alligator-filled moat between the United States and Mexico. (“And make it a real big moat.”) So, in the spirit of political fact-checking, I called an expert, Frank Mazzotti of the University of Florida, who said that the cost of keeping the alligators alive in that climate “would be astronomical.” If there turned out to be a spot along the border where the alligators were comfortable, Mazzotti said, they could escape, multiply and create “all sorts of economic problems.” Not to mention the danger to household pets.

Of course, the likely infestation of alligators along the U.S./Mexican border increases the importance of clarifying the answer to this question.