I think the short answer to that is Medicare, which certainly qualifies as a "national healthcare program."
Can you name one judge or one member of the House or the Senate who is willing to claim that Medicare is unconstitutional? I can't think of even one - not one.
That's why I say that the only way the American people can get the federal government out of the healthcare system is to engage in a massive boycott of the entire healthcare system.
You may not understand that many federal spending programs are unconstitutonal, these programs having been established under Constitution-ignoring socialist FDR in the 1930s and 40s. FDR was reelected enough times that he was able to nominate state power-ignoring activist justices who promoted FDR's unconstitutionally big federal government.