A New Jersey suburb known for its tree-lined streets and stately, multimillion-dollar homes has been transformed into a battleground over both a proposed mosque and the free speech rights of residents who oppose the project. ADVERTISEMENT Bernards, a township of about 27,000 an hour west of New York City, has been cleaved by controversy since 2011, when its Planning Board took up a proposal for a 4,250-square-foot mosque in a residential neighborhood known as Liberty Corner. The applicant, Islamic Society of Basking Ridge, is led by a former Bernards mayor and has filed a federal civil rights suit accusing members...