Here are some facts about the 2016 presidential election:

Most would agree that the four most important states in President Trump’s victory were Pennsylvania, Michigan, Wisconsin and Florida. In those four states, the share of voters who said in exit polls that they considered themselves liberals were 27%, 27%, 25% and 25%, respectively. In each state, the share of voters who called themselves moderates was at least 10 percentage points higher.

And in the three of those states where voters were asked about health care, the share who said Obamacare went too far was significantly higher—more than 10 percentage points—than the share saying Obamacare didn’t go far enough.

So here is a question about the 2020 presidential race: Why do Democrats think they can win back such states with a more liberal agenda, one built in particular around going much further than Obamacare toward a Medicare-for-all, government-run health system?

That is the political puzzler that emerges after last week’s initial Democratic Party debates. In those debates, two camps emerged: a majority of the candidates seemed to fit into a progressive camp that would move the party to the left, and a minority of candidates fit into a more-moderate mold, who would root the party more in the center.