When the local community board in late May approved a proposal to establish an Islamic center amid the strip clubs and liquor stores of downtown Manhattan, the outrage did not come from offended Muslims. Instead, a litany of protests came from a variety of groups — some inspired by Tea Party ideology, others by still-tangible memories of the Sept. 11, 2001 attack on the World Trade Center a few blocks south of the proposed location of the center, and many by undisguised xenophobia. Though not actually at the site of the vanished twin towers, Park51 came to be known as the "Ground Zero Mosque," with its every financial and religious transaction scrutinized microscopically and sharp political divides emerging around it. In the process, it became the emblem of an ugly nationwide debate over the assimilation of Muslims into America and the limits of the so-called American melting pot.