Reminder: betting markets have Bernie as the *most* electable candidate.

[muriel_volestrangler]

70. No, this is not about the "percentage of Democrats he gains"

It's about what the market currently thinks about (a) Democratic candidates' chances of winning the nomination (b) the chances of that winner then becoming president. Not a "percentage of Democrats" (and it's not about a sample, so your revised hypergeometric calculation in #63 does not apply).

For Sanders, the figures (when the OP was written) were 0.58 for the nomination, and 0.34 for the presidency - which is an event which depends on the first happening (unless you think there is a chance of him winning it as an independent), so it is indeed 0.34/0.58=0.586 that the market reckoned for the second stage of "winning the general election after having won the nomination".

Using current figures, the chances for the major candidates are (though rounding with all apart from Sanders cause some problems):
Sanders = 0.37/0.65 = 56.9%
Bloomberg = 0.07/0.15 = 46.7%
Biden = 0.06/0.13 = 46.2%
Warren = 0.03/0.04 = 75%
Buttigieg = 0.03/0.05 = 60%
https://www.predictit.org/markets/detail/3633/Who-will-win-the-2020-Democratic-presidential-nomination
https://www.predictit.org/markets/detail/3698/Who-will-win-the-2020-US-presidential-election

Strictly, as you've pointed out, this is about each of them beating "whoever the Republicans nominate" (and whoever any 3rd party candidates are), rather than "Trump".