response to public funding of ID

The fact that they were themselves religious men has nothing to do with the establishment clause of the Constitution (which they themselves put in the Bill of Rights). The funding toward a religious exercise from public monies is in direct violation of church and state separations. As a result it is necessary for creationist backers to come up with an actual theory if they want it officially taught in science classes of public schools. There is lengthy legal precedent effectively destroying the scientific legitimacy of creationism or for creating bans on teaching evolution in science at all.

ID is not a scientific theory, it is a hypothesis based on creationism and a few broadly misunderstood complaints about the theory of evolution (none of which are legitimately scientific concerns, they're all very human, emotional or faith-based concerns). If it ever becomes a legitimate theory, I would welcome it into a science class room but I wouldn't hold my breath waiting for evidence in support of it. I expect quite confidently it will never become theory because it is a perversion of the scientific method.

There is nothing preventing religious people from teaching their own children whatever they want or sending their children to special religious schools to learn there. That's the second part of separation of church and state: free exercise.