Argument: Gays strengthen marriage by desiring it
"The case for gay marriage." The Economist. February 26th, 2004: "Gays want to marry precisely because they see marriage as important: they want the symbolism that marriage brings, the extra sense of obligation and commitment, as well as the social recognition."
Ted Olson. "The conservative case for gay marriage." Newsweek. January 12, 2010: "The fact that individuals who happen to be gay want to share in this vital social institution is evidence that conservative ideals enjoy widespread acceptance. Conservatives should celebrate this, rather than lament it."