The title of Ezra Klein’s post is “An interview with Mark Pauly, father of the individual mandate.” You should read the interview to find out why (if you don’t know). Here’s a portion:
Was the constitutionality of the provision a question, either in your deliberations or after it was released?
I don’t remember that being raised at all. The way it was viewed by the Congressional Budget Office in 1994 was, effectively, as a tax. You either paid the tax and got insurance that way or went and got it another way. So I’ve been surprised at that argument. But I’m not an expert on the Constitution. My fix would be to simply say raise everyone’s taxes by what a health insurance policy would cost — Congress definitely has the power to do that — and then tell people that if they obtain insurance, they’ll get a tax break of the same amount. So instead of a penalty, it’s a perfectly legal tax break. But this seems to me to [be] angelic pinhead density arguments about whether it’s a payment to do something or not to do something. (Emphasis mine.)
Mark Pauly is quite reasonable and not entirely supportive of the ACA (nor am I, but he’s even less so). To me, that makes his take on the mandate more likely to be based on reason and the merits and less so based on which party passed the law. In general, I find nuanced thinking a hallmark of credibility. Few things are all terrible or all wonderful.