One thing I’m not sure about is if President Trump has ever understood, even if he subsequently forgot, why people keep asking him about pre-existing conditions. Every single time the question comes up, he treats it exactly like any student who gets called on in class, doesn’t know the answer, and then tries to bullshit their way through.

The issue shouldn’t be overly hard to grasp. It makes no sense to insure people against getting ill if they’re already ill. It’s like selling flood insurance to someone whose property is already flooded or fire insurance to someone whose business is already on fire.  So, in order to convince insurance companies to cover people who are clearly going to be unprofitable, the government forces tons of young, healthy people to get insurance, and this offsets the losses.

None of this is necessary if you eliminate private for-profit health insurance and go to a fully government-run plan, but it’s an unavoidable fix for the problem described above. Of course, this means that everyone is mandated to get health insurance, even if they’d prefer to risk going without it.

Eliminating the Affordable Care Act takes away the legal mechanisms that make this work, and leaves insurance companies in an unsustainable position. They can’t continue to give sick people health coverage if they’re not getting a lot of healthy customers to compensate them. They also can’t get nearly as many customers without generous government subsidies (the “affordable” part of the Affordable Care Act).

Republicans don’t like mandating that people buy insurance, and they’ve already zeroed out the tax penalty that is supposed to work as the incentive enforcement mechanism. They don’t like paying out the subsidies. But eliminating the Affordable Care Act doesn’t change anything about how this all has to work if private health insurance companies are going to cover people with pre-existing conditions. Getting the Supreme Court to rule the law unconstitutional, as the administration is attempting to do at the moment, would likely make it even harder for the Republicans to find some alternative way to cover sick people.

So, when Trump is asked how he plans to cover pre-existing conditions, what people are really wondering is how he can convince an insurance company to insure someone with cancer or diabetes or cerebral palsy when they know they’ll pay out possibly hundreds of thousands of dollars more than they’ll ever bring in in premiums. President Obama had an answer for that question, and it’s called the Affordable Care Act. The Republicans in Congress tried and failed to find some alternative way of converting pre-existing conditions and they failed. Trump has no answer, because there is no answer.

People will keep asking him this question straight through Election Day, because it’s very important to millions of Americans. Maybe he hems and haws about this because he hasn’t done his homework, or maybe it’s because there’s just nothing he, or any other Republican can say to reassure the electorate.