First, kudos for this proposal. An extra benefit I see arising merely from its existence is encouraging state and local government agencies to also go HTTPS-only.

Here's my (no doubt naive) question: if this proposal gets approved and implemented, would it automatically apply to non-executive branch websites (house.gov, loc.gov, supremecourt.gov, etc.)? Or would those agencies currently be free to ignore HTTPS if they so chose? What about public .mil sites?