Although I think Justice Roberts is an honorable man, I think he has fallen into a mindset of 'proving' to the country that the Supreme Court is in fact still a non-partisan court. His first endeavor in providing this proof was when he reworded the Obama care bill (the ACA) to make the wording say "tax' instead of the word "fine" as it was originally written. As written with the inclusion of the word "fine", it would not have been found 'constitutional' since the IRS cannot levy fines, but by changing the wording to "tax" it was found to be constitutional, and Obama care became the law of the land, which meant that Justice Roberts had sided with the liberals. In the justice's mind he showed the world that SCOTUS was non-partisan and has followed suit several times since then.
I believe that in his mind he is preserving the integrity of SCOTUS, when in fact if his votes are observed closely and some of his writings are considered, it's pretty obvious to most what his efforts are for. This doesn't necessarily make him a bad man, or a wrong man, just a man with a heart felt desire to preserve the intent and reputation of SCOTUS.
No, I don't know any of this as fact, just as the most logical explanation for some of his unanticipated votes. One more conservative minded jurist on the court, and maybe we will finally see a court again that will make calls of 'constitutional' and/or 'unconstitutional' based strictly on the current wording of the Constitution, instead of how some would prefer the Constitution was worded. I personally don't care if SCOTUS rulings lean conservative or liberal, as long as they are ruled on by the current wording in our constitution. If and when our constitution needs changing, Art. 5 lays out the right and legal process. Judges legislating from the bench, and bench, is not the right or legal way.
Just my thoughts and something to ponder.
regards,
jumpinjoe