The California Supreme Court struck down the same-sex marriage ban as unconstitutional.
Regardless of how you feel about this issue, it's going to be the norm. The Constitution does not allow the government to discriminate against people based on their lifestyle
This may not be spelled out in the Constitution, but it can be implied from it like other rights, like privacy.
Marriage is a fundamental right, so strict scrutiny applies. Restricting marriage to different sex couples violates the fundamental right to marry of those who are gay.
The mistake people make with this issue revolves around the "Gay" aspect. That issue is really a non-issue. The real issue is marriage and the rights to it.
The right to marry is fundamental, so restricting the right based on sexual orientation is per se a violation.