McConnell emphatically told Trump "No" on the healthcare thing before the election. For obvious reasons. So Trump changed his tune to after 2020.
Dems could capitalize on this simply by saying this needs to be done now, people's lives are at risk, etc etc but they probably won't. I can see the catch phrase now: "Why wait?" I'd personally go with "Do or die" and present living examples. Trump pulls on hate strings so the Dems should pull on heart strings.
This is also, of course, in Warren's wheelhouse if they focus on bankruptcy filings due to healthcare costs.