As I understand it there are a number for mandates plural in that law. So he is in favor of that one. And it is one that can be disconnected from the others. In fact preexisting conditions requirements were part of every republican alternative plan I ever heard of.
They set up special pools for insurance at a state level so that, for example, little kids with terribly expensive cancer treatment, continue treatment even if their parents for some reason must change jobs.
It won't work unless there are government subsidies for the insurance companies (I suspect that is the GOPe solution) or everyone in the country is required to pay for health insurance whether they need it or not.
If Trump meant the pre-existing coverage only mandate without the individual mandate, then how is he proposing to pay for it? Higher premiums for everyone (which would mean a lot of heathy people who now have insurance would drop out of the plans until they get some expensive disease)?
Taxpayer subsidies for the insurance companies to help them pay for the people they are forced to cover?
Or just force everyone to buy insurance or pay a fine which would be used to offset the costs and subsidize the insurance companies.
Unless there is a mandate for everyone to have insurance now, then there is simply no way for a pre-existing mandate to work.
If you disagree, then tell me how it would work without one or more of the solutions I have put forth.
Are you really for a federal government "mandate" or are you just defending Trump?