What gives? Well, let Ed Haislmaier of the Heritage Foundation try to explain it for you:
Ed Haislmaier, a health care policy expert at the Heritage Foundation (the conservative think tank that first championed the mandate), said he did not have enough information to comment on Gingrich's past approach to health care reform. Haislmaier did, however, note that there is a distinction between taxing individuals for not buying insurance and requiring them to post a bond, as Gingrich proposed. While the former is a penalty for not getting coverage, "what [the latter] is saying is you have to pay your bills if you get care," he said.
A bond, as Haislmaier noted, is exactly what Romney initially proposed while he was governor of Massachusetts. Romney ended up signing off on a more traditional mandate only after it was passed by the state legislature.
OK, but requiring people to post a bond (rather than pay a tax) if they don't purchase health insurance is regulating inactivity, too, isn't it? I mean, as I understand the constitutional challenge to the health care bill, the person who is forced to post a bond because they won't buy insurance isn't doing anything, right? And, to quote my friend Randy Barnett, isn't such a proposal an "unprecedented" expansion of the commerce power?