WASHINGTON — Mitt Romney and his strategists expected his Mormon faith to fade as an issue for fundamentalist Christians during his first presidential campaign. This time around, should he choose to run again, they have doubts. ...But even as the national Republican establishment warms to Romney as never before, the former candidate and his closest aides now believe a group of voters will always be off-limits because of his religion. SNIP In Iowa, three-fifths of caucus-goers considered themselves “born-again or evangelical Christian,’’ according to a survey, taken for a media consortium as voters entered the caucuses. SNIP More than one-third...