Connection Between Gay Marriage & Interracial Marriage

Gays and lesbians are not allowed to marry in the United States, except in the State of Massachusetts. Most of the arguments against gay marriage are based on religious teachings. These same arguments were used to prevent interracial marriages in this country. Why can't people, who now agree that outlawing interracial marriage, is discriminatory see the connection? Atheism Guide Austin Cline explores this question.