Craig Blomberg recently announced that he's a Calminian, which turns out to be a Molinist with a creative new name. Molinism is a mediating position between open theism and Calvinism. Calvinists believe that God knows the future because God has planned it all out in a way that God's initiative leads to everything that happens in some sense. Open theists believe that God doesn't know everything that will happen, because human free choices are unpredictable. Molinism is an attempt to retain the libertarian freedom whereby we can choose things in a way that nothing (or nothing outside us) causes those choices, God included, while insisting that God can still predict what we'll do.
God knows what we will do because God has what philosophers call middle knowledge. God knows what any free being would do under any circumstance. So God knows what I would have been doing right now if I had chosen to apply to graduate school in my senior year instead of a year later, because he knows what all the free choices of every person in the world would have been in that scenario and can trace out what they all would have done in the time since. The way God remains sovereign is that God can arrange events in such a way that people will freely choose the things God intends them to choose. So the degree of control God possesses is as strong as Calvinists think, but the causal relationship between God and the choice is much weaker.
Molinism can't work, because it fails in one key aspect. It assumes certain kinds of truths that can't exist if we have libertarian freedom. Libertarianism requires a genuine possibility of doing any of multiple options. If there's a fact about what I'll do in certain situations, then I don't have libertarian freedom. Philosophers call these facts about what I'll do in a certain situation counterfactuals of freedom. According to Molinism, there'a a counterfactual of freedom for any possible scenario. That means there's a truth of what I would do in any situation. The question is what explains why these counterfactuals are true. It can't be any facts about the world as it exists now or in the past, because then I would be caused to act in a way that libertarians deny. It can't be facts about the future, because free choices aren't explained by backward causation. If there's any fact that explains the truth of these counterfactuals, then it threatens predetermination, and we're left without libertarian freedom. So to preserve libertarian freedom, we'd have to deny that there's anything that makes these counterfactuals of freedom true. Nothing at all explains why there are such counterfactual truths. But if nothing explains why they would be true, then there must not be any true such counterfactuals. So middle knowledge is impossible if libertarianism is true.
Now I don't think libertarianism is true. I don't think freedom requires this absolute power to do something contrary to what we actually do. Libertarians insist that our choices can't be explained by any events within us, but I think freedom makes no sense unless our character and internal nature lead to our choices. When I want my choices to be free, what I want is for my own desires and character to lead to what I do in the right sort of way. So freedom doesn't conflict with being caused. It requires it. This compatibilism about freedom and predetermination is exactly what Calvinists have long insisted on. A Calvinist has no problem accepting middle knowledge, also. God certainly does know what free human beings would do when faced with any particular situation, so God knows what I would do in any alternative situation from what I actually do face. Middle knowledge isn't incoherent. It's just incompatible with libertarian views of human freedom. Thus it doesn't rescue exhaustive foreknowledge and libertarian freedom in the way Molinists want it to.
So that's the view that Craig says he's adopting when he says he's a Calminian, and that's why I don't think it really does what it's supposed to do. But there are several things he goes on to say that don't make any sense to me.