But they do play politics. That's the only way you can explain them upholding the ACA, which was passed with no resemblance to the Constitution.

The Constitution is only about eight pages long, so do go out and read it. You will see that spending bills MUST start in the House. Bills must pass successfully through BOTH houses of Congress before they can go to the President.

The ACA was started in the Senate (violation!) and was never voted on by the House (because it would have lost there). The Supreme Court should have struck it down on those grounds alone. Regardless of whether the challenge even brought up the illegality of the way it was passed, the Court had an obligation to first and foremost uphold the integrity of the Constitution. They did not. Why not?

Politics!