As more states legalize same-sex marriage, one of the key questions the justices may be forced to address is whether a national consensus now exists supporting the idea of expanding a "marriage equality" right to homosexuals.

CNN: Gay couple fights for right to marry in epic high court fight

As more states legalize same-sex marriage, one of the key questions the justices may be forced to address is whether a national consensus now exists supporting the idea of expanding an "equal protection" right of marriage to homosexuals.

CNN: Obama administration weighs in on defense of marriage law