Pictured: somebody who DEFINITELY swings for the fences instead of just calling balls and strikes.
While trying to predict the results of Supreme Court cases is a crap-shoot, there is one underlying fact that can accurately predict which way Chief Justice John Roberts will vote on any given case. That fact is Justice Roberts will do anything he can to enhance the Republican Party's advantages at the ballot box. Follow past the weird, curly strike zone to see what I mean.
It is no secret that Roberts is a partisan hack that lied through his teeth during his confirmation hearings. See here for a reminder of just how much of a liar he is.
As we have seen from Citizens United, he is very well-prepared to "legislate from the bench", throwing out precedent and laws passed through the democratic process to achieve the desired end. The means Roberts employs are always justified in his view, but since Justice Kennedy is the only real obstacle to getting the 5-4 decisions he wants, his job is rather easy. Citizens United is one of Robert's most blatantly partisan actions, but this rabbit hole goes even deeper.
For instance, his Hobby Lobby decision was another dramatic upheaval of U.S. Law decided by a narrow 5-4 majority. Some may argue that his reasoning for joining the majority on this case is simply a consequence of his time in the Reagan Administration and the anti-women legal opinions he authored during his tenure. However, we need to remember that many in the Religious Right are getting impatient with the slow "progress" (or should I say "regress") on reproductive rights in this country. This huge chunk of red meat, based on giving corporations more freedom to screw over their workers no less, has been the strongest reminder to the Religious Right and their foot-soldiers in recent memory that their efforts will eventually bear "fruit". Forget the Equal Protection Clause or the myriad problems involved with giving corporations religious freedom; Roberts is mainly concerned with keeping the Fundies from getting disillusioned with the political process.
On to another case: NFIB v. Sebelius. Now, you might think I'm crazy bringing up the case where Roberts swooped in and "saved" Obamacare when arguing for his partisan hackery, but hear me out. His decision was a genius partisan move 3 different ways to Sunday. Firstly, he made sure his decision hinged around calling the penalty for not satisfying the Individual Mandate a tax, something that echoed around in the media and cemented the public's opinion that the Affordable Care Act (ACA) was a massive tax increase. Keep in mind this decision came out during the height of the 2012 election and reinforcing the perception that Obamacare = tax was a highly-effective move to help the floundering Romney campaign. Robert's 2nd stroke of partisan genius was to realize what his options were. Preserving the ACA would keep the teabaggers fired up and willing to pull the lever for the odious Romney regardless of how unlikable he was. Conversely, preserving the ACA kept the 50% of the country that approves of the law from getting up in arms about the issue and increased the odds that they would stay home on election day. Just imagine how "fired up and ready to go" even the most disillusioned liberals on this site and across the country would have been had Roberts struck down Obama's key policy achievement! Finally, making the Medicaid Expansion optional under this decision meant that millions of people in GOP-controlled states would be denied expanded health coverage, souring them on the law's efficacy and making them even more cynical about the political process. If you hear all this hoopla about "Obamacare" and nothing really changes in your life, odds are you probably won't put the pieces together and see how it was really the GOP and their partisan allies that deprived you of coverage.
There are more examples, but you get the point: Roberts can be counted on to maximize the GOP's electoral advantage at every opportunity regardless of legal precedent or established law. This brings us to the current King v Burwell case being argued before the Court. A lot of good diaries and articles on DK and other sites have gone through the case law, combed the legalese and presented a strong case for why King v Burwell is utter bullshit and should have never made it to the Court in the first place. While this matters somewhat, I've just shown that legal precedent and established laws / customs do not matter to Roberts all that much when a partisan advantage can be gained through a Supreme Court decision. Agreeing to take this case in the first place helps ignite passion in the GOP base that is crucial to getting the ball rolling on their presidential nomination process. However, there is a partisan advantage in not taking away health insurance tax breaks for people in the federal exchange.
Should the King case strike down tax breaks for health insurance, the consequences for the Republican Party would be severe. (and they are tax breaks...I don't know how in the hell people keep calling them "subsidies" even though they're the same thing. It seems like only the wealthy and big corporations can get "tax breaks" while anybody else that gets more money due to government policy is receiving "subsidies". Clever framing going on here, but I digress.) Suddenly, most of the problems with the ACA would be blamed on the GOP. I mean, they mostly are caused by Republican meddling, poison pills and obstruction, but just imagine when the media actually starts calling them out on their bullshit instead of just letting them get away with it. The GOP-controlled House and Senate have no feasible plan to replace the tax breaks or even provide a bridge to some other malarkey-laden "plan" they might come up with...sometime, whenever they feel like it. State-level Republicans are in a similar situation as well. To put it simply, the optics of this fiasco would outweigh any of the shutdowns or other hostage-taking these clowns have pulled over the last 4+ years.
In summary, expect the ACA to still be mostly intact after the King decision, but not for any reasons that the legal scholars out there are thinking of. Should Kennedy side with the sane justices on the Court, this will free Roberts up to write a scathing dissent to please the teabaggers and preserve the sick vision of his historical legacy. Should Kennedy slip back in among the Scalia Gang for this decision, count on Roberts to keep the law alive but set up another back door for the GOP and their political foot-soldiers to lay siege once again sometime in the future.