Perhaps surprising, perhaps not, but the "publicreligion.org" website reports a study that found that Roman Catholics are pro LGBT:
Catholic Attitudes on Gay and Lesbian Issues: A Comprehensive Portrait from Recent Research
Catholics are more supportive of legal recognitions of same-sex relationships than members of any other Christian tradition and Americans overall. Nearly three-quarters of Catholics favor either allowing gay and lesbian people to marry (43%) or allowing them to form civil unions (31%). Only 22% of Catholics say there should be no legal recognition of a gay couple’s relationship.
When same-sex marriage is defined explicitly as a civil marriage, support is dramatically higher among Catholics. If marriage for gay couples is defined as a civil marriage “like you get at city hall,” Catholic support for allowing gay couples to marry increases by 28 points, from 43% to 71%. A similar pattern exists in the general population, but the Catholic increase is more pronounced.
Beyond the issue of same-sex marriage, Catholic support for rights for gays and lesbian people is strong and slightly higher than the general public. Nearly three-quarters (73%) of Catholics favor laws that would protect gay and lesbian people against discrimination in the workplace; 63% of Catholics favor allowing gay and lesbian people to serve openly in the military; and 6-in-10 (60%) Catholics favor allowing gay and lesbian couples to adopt children.