For someone of Dr. Horton's stature to be saying something like this is awful.
I understand the complexities of applying Scripture to politics — I really do. If it were easy, we wouldn't have had debates on the matter in Christian circles since the days of Constantine. For those of us in Reformed circles, we need to keep in mind the Southern Presbyterian “spirituality of the church” tradition; not all errors are heresy, and this new “Two Kingdoms” theology, at least in its moderate rather than R2K form, has parallels to the older Southern tradition.
But what has happened with Dr. Horton shows that we're in danger of losing sight of the forest for the trees. Wagglebee is right — homosexuals need to be called to repent. To say the state should consider allowing some form of domestic partnerships for homosexuals is to say the state should consider officially endorsing sinful behavior.
Why is it so hard for some Christians to understand that the state should not be officially endorsing sin?
It shouldn't be.
I think that ultimately our society will adopt a temporary compromise on this topic. I'm NOT endorsing this compromise by any means but simply stating where I see the trajectories headed.
The church will go silent on the issue of civil unions, domestic partnerships, or whatever title the state wishes to use for homosexual "marriage". In exchange, the state will allow the churches to continue to define marriages according to God's Word and protect their right to do so. I think that enough churches would be okay with the idea that they'd accept it to avoid the threat of protracted legal fights when two people demand their right to be "married" in a church ceremony. Also, the church, as a whole, might like to disengage from this argument which she sees as going against us in the court of public opinion. I think that the gay movement would be happy to just consolidate the gains it has made and the church would like the relief.
It will be an uneasy "peace" that will be broken ultimately. The gay movement doesn't want acceptance of their ideas, they want their ideas to dominate, even if it has to be imposed on the unwilling.
Until we see a true revival in our evangelical churches, I do not see the church universal fighting effectively on this issue. When we have respected church leaders like Dr. Horton seemingly reluctant to go where God's Word clearly leads, the church has problems.