Times have changed. On two recent occasions, CEOs of prominent corporations were asked for their credit cards to pay for a White House lunch to which they were invited. Surely they expensed the mid-day meals to their company accounts, but the instances have made news because they're without precedent.
White House spokeswoman Jen Psaki explained, "From time to time, White House guests are asked to reimburse for their meals in order to ensure there is no conflict or appearance of a conflict. That is consistent with our tough ethics rules, and we will continue the practice when appropriate."