Obamacare is back before the Supreme Court on Tuesday, with opponents challenging it for a third time. The first attempts to derail the law failed in the high court by votes of 5-to-4 and 6-to-3. But the makeup of the court is very different now, with three justices appointed by President Trump – among them new Justice Amy Coney Barrett.

Before her nomination, Barrett consistently criticized the court's two previous decisions, a critique that Senate Democrats repeatedly bludgeoned her with at her confirmation hearings.

But the ACA has remained in place for a decade, and the legal landscape has changed so much over that time that many of those who originally took issue with the law in the Supreme Court think this challenge is a stretch. In fact, most of the groups that fought the ACA after it was enacted in 2010 are missing in action from Tuesday's case.

The most controversial part of the ACA when it passed was the requirement that people either buy health insurance or pay a penalty. In 2012, Chief Justice John Roberts and the court's other conservative justices ruled that the individual mandate exceeded Congress' power to regulate interstate commerce. But Roberts provided the fifth vote to uphold the penalty anyway on the grounds that it amounted to a tax and thus fell within the taxing power of Congress. Bottom line: The mandate survived.

Now comes another challenge to the ACA, brought by Texas, other GOP-dominated states and most significant of all, the Trump administration. They assert that because the penalty has been zeroed out, it raises no revenue, is no longer a tax and thus is unconstitutional.