There has been considerable discussion in the letters section of the Tri-City Herald on the topic of same-sex marriage and Referendum 74. If marriage equality opponents do not submit enough valid signatures to put this issue to a vote of the people, marriage equality will become Washington law on June 6.
Most of the opponents of same-sex marriage appear to base their reasoning, either explicitly or implicitly, on religious grounds that consider homosexual behavior to be immoral.
A May 4 letter by John Sisk criticized the Washington Legislature for what he saw as its straying from a definition of marriage that was procreation-centered. He argued that the "optimum environment" for raising children was with a father and mother in a "family structure" and urged people to support taking this issue before the voters.
People get married for a wide variety of reasons other than raising children. I'm not aware of statistics demonstrating that children raised in same-sex (or single-parent) households are less well off in general than their counterparts.
Surely, the ability of same-sex partners to enjoy the legal rights granted married couples does nothing to detract from someone else's ability to raise their own children.
David Feller, Richland