The underlying reason gays want the right to marry is they want the financial benefits traditionally provided to married heterosexual couples, such as discounts on insurance, etc. Once the gays get enough states to recognize gay marriage, they will seek approval at the national level, thereby giving them benefits such as Social Security for a surviving spouse and children, and federal tax breaks.
At least in Washington state, the domestic partnership law specifically excludes related couples (such as two sisters or a brother and sister) who share a household from receiving any of above mentioned financial benefits.
Example: If two adult siblings with children share a household, they receive no financial benefit. If a gay couple with children shares a household they receive the same benefits as a married couple. I am not suggesting that related people be allowed to marry. I am saying that if we truly place a value on families, the expansion of benefits should be available to all families.
I join with millions of people who oppose redefining the definition of marriage. Since our societal definition of a family unit has changed, I support allowing the expansion of benefits via a civil union or similar legal contract, but only if it applies to all couples who share a household.
Same-sex couples can get a durable power of attorney for health care if they want each other to get information when they’re hospitalized.