Bluntly telling the Vatican to stay out of American politics, U.S. Sen. John F. Kerry yesterday said Pope John Paul II ``crossed the line'' by instructing pols to block legalization of gay marriage. A fuming Kerry, taking on his own Catholic Church in the midst of a campaign for president, said Rome should have more respect for America's long-held separation of church and state. ``It is important not to have the church instructing politicians. That is an inappropriate crossing of the line in this country,'' Kerry said. ``President Kennedy drew that line very clearly in 1960 and I believe we...