Actually, YOU left out the first logical step.<quoted text>
Actually, you left out the first logical step.
In reality, it's the current ability of heterosexuals to marry that is the leading cause for other groups to demand the right to legally marry. Same sex couples are only asking for the SAME right to marry just one person.
However, same sex couples wanting the SAME right to marry one that already exists for ever heterosexual in the country is not similar to straight people demanding the right to marry, not only ONE, but many at one time.
Separate issues. Separate effects on society.
In reality, marriage always has included the likelihood of procreation. So much so that the instances where it did not occur were ignored.
Moreover, you then simply argue tradition, without a valid reason to discriminate.
The only reason marriage was restricted to one man and one woman, was the very issue of procreation. By removing that element, you leave the setting of a natural family undefined, horn in on the protection and support designed for that foundational societal relationship, and open the door to simply any committed relationships. ANY restrictions of number and type must show harm, and children cannot be considered.