Trump has repeatedly said that he wants to repeal Obamacare. But evidently constitutionally low-information Trump, just like many other low-information patriots, probably did not understand that Boehner and McConnell did not have enough votes to override a presidential veto of an Obamacare repeal bill regardless that these RINO lawmakers promised to repeal Obamacare if reelected in 2014.
And he has advocated single payer.