Evolutionary theory has 150+ years of real, tangible, scientific evidence from many different fields to back it up. It makes intuitive sense and makes biological science fully comprehensible to an elementary biology student.
ID on the other hand teaches what exactly? What point do you wish to get across to the students? Life was designed? By whom? How? For what purpose? Can a biology teacher really answer these questions in the context of a high school science class? These questions will be asked. And if you really want to do some damage to your cause, bring up Noah's Ark, the Flood and a 6000 year old earth in science class as well.
If you ask impressionable children to choose based on scientific criteria, I absolutely promise you and other religiously motivated people are *not* going to like the result.
Giving children a choice between candy and spinach for supper works about the same way.....