I’ll give you a couple of hints. First, he’s a famous Constitutional scholar.  Second, he’s rumored to be the smartest elected official evah.  Third, he, er, obviously doesn’t take his own advice.  Gretchen Carlson from Fox & Friends introduces this clip that shows Barack Obama almost eerily framing the very argument that Judge Robert Vinson used to overturn Obama’s signature legislation, from an appearance in February 2008 on Ellen DeGeneres’ daytime talk show (via Greg Hengler, h/t Vayapaso):

Obama was specifically rebutting the individual mandate in Hillary Clinton’s health-care proposal:

She’s have the government force every individual to buy insurance, and I don’t have such a mandate because I don’t think the problem is that people don’t want health insurance.  It’s that they can’t afford it …

Well, if things were that easy, I could mandate everybody buy a house, and that, you know, and that would solve, you know, the problem of homelessness.  It doesn’t.

CNS has a longer clip, in case the one above is a little dodgy. It also contains his entire answer, although that shows the edit on the first to be fair:

Nor was that the only time Obama made that argument.  Earlier that same month, he told CNN the same thing:

OBAMA: Let’s break down what she really means by a mandate. What’s meant by a mandate is that the government is forcing people to buy health insurance and so she’s suggesting a parent is not going to buy health insurance for themselves if they can afford it. Now, my belief is that most parents will choose to get health care for themselves and we make it affordable.

Here’s the concern. If you haven’t made it affordable, how are you going to enforce a mandate. I mean, if a mandate was the solution, we can try that to solve homelessness by mandating everybody to buy a house. The reason they don’t buy a house is they don’t have the money. And so, our focus has been on reducing costs, making it available. I am confident if people have a chance to buy high-quality health care that is affordable, they will do so. That’s what our plan does and nobody disputes that.

Judge Vinson actually references the latter example in a footnote in his opinion overturning ObamaCare, warning against an overbroad reading of the Commerce Clause:

The problem with this legal rationale, however, is it would essentially have unlimited application. There is quite literally no decision that, in the natural course of events, does not have an economic impact of some sort. The decisions of whether and when (or not) to buy a house, a car, a television, a dinner, or even a morning cup of coffee also have a financial impact that — when aggregated with similar economic decisions — affect the price of that particular product or service and have a substantial effect on interstate commerce. To be sure, it is not difficult to identify an economic decision that has a cumulatively substantial effect on interstate commerce; rather, the difficult task is to find a decision that does not.23

So it turns out that Obama actually is a Constitutional scholar … or, rather, he was.