A widely held assumption about Roberts is that he typically leans as a conservative justice on the Supreme Court who would almost certainly strike down the individual mandate of Obamacare (and thusly, the entire law). But Roberts is beholden to the legacy of his leadership on the Supreme Court and is likely well aware of this case's importance.
Kennedy, who is considered the swing vote for this case, could just as easily uphold the law as he would decide to oppose it.
"He could be looking at this as, 'OK, let's just think in terms of what the federal government is doing here, whether it's really out of line with the federal government has done in other situations,'" says Greg Magarian, a Washington University in St. Louis law professor who clerked for former Justice John Paul Stevens.
Magarian, like many others, thinks if the court upholds Obamacare that it would be by a 5-to-4 decision; however, Greely says that it would be 6-to-3 if upheld, because he believes Roberts would go along with Kennedy on the issue.
The Supreme Court could just as easily strike down the law as a whole.
Kennedy and Roberts did cast serious doubt about individual rights and the powers of the federal government.
"Even liberals -- even the Ruth Bader Ginsburgs -- if they're intellectually honest they'd have to say, 'Well, even we acknowledge that there have to be some checks on what Congress can do and can't do," says Jack Burkman, a Republican strategist in Washington. Burkman thinks the court will decidedly oppose Obamacare either 7-to-2 or 8-to-1.
Justice Antonin Scalia made one of the most cited comments this week at the oral arguments when he mentioned the need for broccoli. Everybody must buy food to survive, Scalia argued, so there's a market for food. He continued that since everybody is in the food market, the government, by his interpretation, could force people to buy broccoli.
Central to the argument against Obamacare is where the court can draw a distinct line that would set a viable precedent for the future. If the court upholds the ACA, the justices almost certainly asked themselves how their decision would be used in future cases that chose to invoke the precedent being set.