Comey calls on Americans to 'use every breath we have' to oust Trump in 2020

[Jim Lane]

22. There's a problem with "Pick the candidate most likely to beat Trump"

He seems to be deprecating the sincere ideological disagreements within the Democratic Party (e.g., on Medicare for All) and suggesting that the principal or sole criterion should be identifying the candidate with the best chance of winning the general.

The problem is that it's never clear-cut who that candidate is. As a complication, people trying to figure it out are heavily influenced by their own ideology.

In 2016, these were two very common points of view:
* Democrats who were more conservative (e.g., saying that Medicare for All would never, ever happen) were clear that, polls as of July notwithstanding, Bernie Sanders as the nominee would be a general-election disaster. A Republican campaign blasting him as a socialist would yield 400 electoral votes for Trump.
* Meanwhile, Democrats who were further left on the issues were clear that Hillary Clinton was the candidate most vulnerable to Trump's preferred style of personal attack. Decades of right-wing scandal-mongering would mean that downplaying substance and blasting her "damn emails" would be a winning GOP strategy.

We get to run the election only once, so we never find out even in hindsight who would be the strongest candidate.