I think that the mandate will be upheld.
I predict there will not just be two opinions (the holding/analysis and the dissent), but will be multiple opinions where the justices concur in the result, and some of the reasoning, but ultimately get to their individual view of how the Constitution and statute operate to reach the result.
Here is my vote breakdown [you can check my votes in June; it's like when Ebert predicts the Oscars]:
[btw, saying what the Justices "think" is my way of saying "that's what I infer from their questions"]
Ginsburg will vote to uphold the mandate. They plainly think that the failure to buy health insurance
plainly affects interstate commerce (plainly both health care and health insurance).
Kagan will vote to uphold the mandate.
Wickard v. Filburn, a 1942 Supreme Court case interpreting the Commerce Clause broadly to allow regulation of purely intra-state commerce (actually home use) because of its effects on interstate commerce. They'll also see a slippery slop to unwinding Social Security.
Thomas will vote that the mandate is unconstitutional. Heaven knows how he'll get there.
Alito will vote that the mandate is unconstitutional. The Constitution is fundamentally a limitation on the powers of Congress.
Under the government's theory, the inactivity in insurance affects the interstate commerce in health insurance and health care.Under that theory, anything is subject to regulation, because all human activity affects interstate commerce [e.g. if you ride the bus rather than drive a car, you raise the cost of cars. If you don't go to college, you raise the cost of goods in many ways, including by producing unskilled labour. If you make music for a living, you increase the welfare rolls, etc. . .]. The parade of horribles is run out to test whether there's a limiting principle, and all the government does is describe the insurance and health care industries. In the absence of a limiting principle that explains why this particular law is special, it can't be constitutional because it confers plenary power on the federal government, which is utterly inconsistent with the purpose of the Constitution. And if plenary, it can't be "proper" under the "necessary and proper" clause (granting broad power to effect other Constitutional aims) because it's inconsistent with the Constitution's purpose.
Kennedy will vote that the mandate is constitutional.
Roberts will vote that the mandate is constitutional. He will have a hard time overcoming the examples he himself provided of other industries (and thus no, or a shaky, limiting principle). But he will craft a clever way to find the health-care industry unique, and to link insurance (perhaps adopting the payment method argument, or joining Justice Kagan in her idea that we don't buy the insurance to look at an insurance certificate, but to buy the health care).
The last two are obviously the tough ones. Kennedy really seemed troubled that this is an argument for limitless power. But he seemed to accept the notion that health care is unique. And while he's not O'Connor -- with her refusal to draw bright lines and straddling all fences to achieve a desirable middle-o'-the-road outcome -- Kennedy does seem to embrace the idea that he is a line of reasonableness necessary to this great land of ours. He won't wanna be the guy that killed a giant piece o' legislation enacted by the people's representatives.
Roberts is also tough. He sees the Act as an exercise of plenary power, and sees that he'll be letting the genie out of the bottle. But his institutional concern for the Court will want to avoid a 5-4 vote striking down such a huge statute, even if the statute is controversial. The attitudes about the law are so overwhelmingly partisan now, and the law has been so politicized, that he won't want to allow the Court to appear to be driven by the politics.
The court isn't, in my estimation. At least not "politics" as we normally think of them. These justices just have fundamentally different views of the purpose and place of the Constitution and the role of the federal government under it. They were nominated because they hold those views, and their views are used by the two parties to achieve those parties' political and policy aims. But the justices aren't particularly driven by those aims. Of course, it appears that it's policy-based, because the justices can't abide a policy that is inconsistent with their view of the Constitution and the federal government, so they are naturally antagonistic to those policies without attention to economics and budgets and methods and such.
Or perhaps I'm a naive fool. But I see them vote against their supposed "party" often, and they do it because of their view of the Constitution and the role of the federal government under that document.
Check back in a couple ' months to see how I did !