Why even homophobes should celebrate gay rights victories

One of my favorite Abraham Lincoln quotes:

As I would not be a slave, so I would not be a master. This expresses my idea of democracy.

If I claim the right to deny you rights, that sets the precedent that someone (maybe you, or maybe someone  else) might deny MY rights.

So a victory for the rights of any minority, no matter how much or how little you may identify with that minority, is a victory for us all.