Preschools have generally been a very successful endeavor to give our children a head start on their education. I personally feel they've been very successful because they are privately funded not government-funded. I know of no public preschools. My guess would be that this is funds available to low income families. Similar to the funds that are available for day care.
Now for privately funded preschools, they can teach whatever they want however they want, because they're privately funded. If there are public preschools somewhere then I totally agree. Why would they teach anything that our country's language. English.
Now I realize that we have a very large Spanish speaking population. And I fully agree that our public schools should offer classes designed to teach Spanish speaking persons the ability to speak and write in English. But there is no way that public funded schools should be teaching any subject other than English in Spanish.
As far is publicly financed preschools, well, why stop there. Why don't we just take the kids as soon as they're weaned and put them in the academy so that they are right-thinking? I mean, they could be taught Obama arithmetic and proper wealth sharing behavior.