MILLBURN, N.J. — Matthew Stewart believes there is a place forcharter schools. Just not in his schoolyard.

Mr. Stewart, a stay-at-home father of three boys, moved to this wealthy township, about 20 miles from Midtown Manhattan, three years ago, filling his life with class activities and soccer practices. But in recent months, he has traded play dates for protests, enlisting more than 200 families in a campaign to block two Mandarin-immersion charter schools from opening in the area.

The group, Millburn Parents Against Charter Schools, argues that the schools would siphon money from its children’s education for unnecessarily specialized programs. The schools, to be based in nearby Maplewood and Livingston, would draw students and