Final answer:
The most liberal group regarding social issues such as abortion and same-sex marriage tends to be religiously unaffiliated, as they generally support progressive values and believe in the separation of church and state in government policy.
Step-by-step explanation:
Regarding social issues such as abortion and same-sex marriage, the group that tends to be the most liberal is the religiously unaffiliated. This group is characterized by a diverse range of beliefs, but overall they lean towards progressive values, particularly when it comes to women's rights to choose in matters of abortion and the rights of individuals in the context of same-sex marriage. This contrasts with Hispanic Catholics, white Protestants, and Black Protestants, who may hold more traditional views shaped by religious doctrines on such issues.
The religiously unaffiliated are more likely to believe that governmental policy should not be based on religious principles, thus supporting more liberal policies on social issues. Public policy is influenced by various groups with differing ideologies. For example, while some Christians oppose embryonic stem cell research, others support it, indicating that views on social issues can vary even within religious groups.