Here's why even pilot programs for school choice are so strongly opposed: Once people see the benefits of even a pilot program, there's pressure for it to grow.

The Wall Street Journal says, on its opinion pages today, that this dynamic has been at work in Florida. In 2001, a corporate income tax credit for education was created, with only one Democratic party legislator in favor of it.

Last month, one-third of the Democratic caucus approved of a plan to expand the program.

What happened?

"Our guess is that low-income parents in Florida have gotten a taste of the same school choice privileges that middle- and upper-income families have always enjoyed."