Some people can pick between Coke and Pepsi in blind taste tests. Only a few can explain what separates bourbon from whiskey. And it often takes a parent to know which twin is which.

Yet nobody — absolutely no­­­­body — can tell the difference between sugar that comes from GMO crops and sugar that doesn’t. You can look at the sugar with your eyes. You can taste it with your mouth. You can even have expert scientists study it at the molecular level using ultra-powerful gas-spectrometer analysis.

And still, nobody can tell the difference.

So why would anybody want the U.S. Department of Ag­­riculture (USDA) to try?

A few anti-biotech activists are demanding that USDA make the futile attempt, as part of a new federal GMO disclosure...