This is not surprising as SBC membership has been steadily declining and this, alongside the overall decline of Christianity in America, is leaving only the most conservative and extreme views behind. This act will only serve to ensure the decline continues as they are really just digging their own grave.

This is such a great observation that it seems obvious as soon as I read it, but it didn't occur to me at all, especially in the sense you have framed:

The decline of Christianity isn't a dissipation, it's a contraction towards the hard core.

Gaming that out leads to some pretty alarming scenarios, and that's relative to the alarming scenario we are currently living through!