Earlier quoted context omitted.
I don't know if we can count on the ACA staying around forever.
It survived both political parties in power. It might get chipped away over the next 30 years or replaced with public option etc, but bringing back the preexisting condition issue would be extremely unpopular. Also, it does not actually cost insurance companies much money as they can all just raise premiums.
And you must be confident that Trump will lose, since the 5-4 majority that saved Obamacare last time will not survive a few more Republican appointments.