The biggest controversy, and the item that pushed the ACA over the goal line, was Chief Justice Roberts siding with his liberal colleagues and approving the law, based on disputed logic that likened the mandate penalty on individuals to a tax, and thus subject to federal approval (and Supreme Court affirmation).  When the federal government decided to eliminate the penalty, they also eliminated the Supreme Court justification for ACA continuation.  That was upheld in a recent US Court of Appeals decision (Fifth Circuit), saying the mandate is now unconstitutional.

Now the states who joined the original suit and the House of Representatives have filed two petitions asking the Supreme Court to weigh in on the issue immediately for both its constitutional position and the ACA viability if the mandate is struck down.