If his definition of marriage is 1 man and 1 woman, and that definition is being changed to 1 man/woman and 1 man/woman it is somewhat logical to wonder why the "1" has to stay.
In other words if we can change the gender part of "marriage" why can't we change the numerical part?
Is there a good reason why it has to remain between 1 and 1? Or is that just us sticking to our preconceived notions just like Moore is sticking to his?
There is not a good reason that the numerical part can't change. Marriage between whatever number of consenting adults is nobody's business who isn't in that relationship.
And it's always hilarious to me when conservatives fall all over themselves to try to use the Bible to prevent gay marriage, while simultaneously decrying gay marriage as a gateway to the apparently-much-worse plural marriage.
Surprisingly, they're a little hazy on the Biblical justification for that last bit. :)