If you're a presidential candidate and you've got a tax plan that you want to promote, it's a good idea to double-check with your "experts" -- especially if they're on the other side -- to see if they really support it.

Imagine my surprise when I discovered that Senator Kerry's campaign cites me -- "conservative economist Kevin Hassett" -- as an "expert" in support of its plan to change the U.S. corporate tax code. Had the Democratic presidential candidate immersed himself in my often tedious writings on corporate taxation and seen the light? About time!

Alas, it was not to be. Kerry doesn't get it. In fact, his proposal makes a bad system even worse for most U.S. multinational corporations. But the story does not end there. He also shamelessly included a loophole that is designed to give billions of dollars in tax breaks to the few companies -- including HJ Heinz Co. (as in Teresa Heinz, his wife) -- that are organized in a particular way.

Oops.