He can still do a lot to marginalize it. He does not have to enforce it first. Second, he can change the law (as long as the budget is not affected) without a supermajority. That's one of the reasons the 2020 catilac tax won't be repealed and just will be postponed. It's just a fiction moneymaker. The obama administration recognized the huge cost of the ACA (even if it was successful, which it has not been), so in order to be able to tell the general public that it's cost neutral they needed more cash. The solution, create a fiction moneymaking legislation that is effective only after your term has expired, thus leaving the problem for someone else but being able to justify your program as cost neutral. We all know that if the tax becomes effective neither employers nor individuals wail pay it, they will simply conform their plans of coverage. More likely, they lobby against it and have it repealed. This tactic was coined by a Bill Clinton during his administration. I would not doubt seeing Trump now make his changes and potentially double the catilac tax and postpone it further. Needless to say, we have a big mess on our hands.