text: Republicans Endorse Ban on Gay Marriage NEW YORK - Republicans endorsed an uncompromising position against gay unions Wednesday in a manifesto that contrasts with Vice President Dick Cheney's supportive comments about gay rights and the moderate face the party will show at next week's national convention.    A panel made up largely of conservative delegates approved platform language that calls for a constitutional amendment banning same-sex marriage and opposes legal recognition of any sort for gay civil unions...