Two nights, two very different Democratic debates, and a deepening liberal-centrist split

If you were a Democrat, and you believed, as many Democrats do, that the nation faces an existential crisis in the form of President Trump, would you want to watch a Democratic debate which opened with ten of your party's presidential candidates stuck in an endless discussion of healthcare arcana?

Yes, healthcare helped Democrats win the House in 2018 and remains important today. But Trump was not on the ballot in 2018. He will be in 2020. To defeat him, Democrats need a nominee who is as big as he is. There might not be any such candidate in the Democratic field today, but if there is, he or she will not be identified by an exploration of how many years it will take to transition to "Medicare for all."