Andrew Sullivan says if we are opposed to gay-marriage we should support a constitutional amendment banning divorce. Because? What's the rationale behind that statement?

Maggie Gallagher of MarriageDebate.com answers Mr. Sullivan in a cogent way in this article. She says it's a non sequitur (something to throw the discussion off track).

Her final paragraphs read:

In fact the whole push for gay marriage looks very similar to the push by legal elites for unilateral divorce. The very same arguments are used: inadequate and preliminary social-science data used to “prove” that divorce has no ill effects on children. Critics who warned that redefining divorce as a unilateral right might increase divorce were pooh-poohed. Only bad, unhappy marriages would be affected, we were reassured. After all, how can the divorce of an unhappy couple affect happily married people? Most tellingly, radical transformation of divorce laws were presented as a conservative, modest reform that would actually strengthen marriage.

Do not believe it. It wasn't true of divorce; it isn't true of gay marriage.