As you can see, Biden is unusually beloved, even for a politician as well-known as he is. The 12-point difference between his actual net favorability rating and his projected net favorability rating places him at the top of the table. But the biggest outlier is Michael Bloomberg, who says he is still deciding whether to get into the race. With 62 percent of Democrats able to form an opinion of him, Bloomberg is one of the better-known contenders. But he has a net favorability rating of only +11 (24 points less than expected). Why is Bloomberg so relatively unpopular? Maybe Democrats are aware of his moderate views on economic issues; for example, he compared Warren’s proposal for a “wealth tax” with “non-capitalistic” Venezuela. Or, maybe, in the era of President Trump, Democrats are turned off by the idea of nominating a businessman for president.

Either way, it’s a problem for Bloomberg, should he decide to run. According to FiveThirtyEight’s research, only one high-recognition but low-favorability candidate early in the campaign has overcome that handicap to win a nomination since at least 1980: Trump.4 The president may not get enough credit for his extraordinary comeback in the primary campaign5 — he turned a -42 net favorability rating among Republicans (!) in a May 2015 poll into a +28 net favorability rating that September. Bloomberg isn’t starting from such a low place, but if he wants to improve his popularity among primary voters, he may have a harder time than Trump did. Although he has the advantage of wealth (like Trump), Bloomberg is unlikely to get the massive quantity of free-media coverage that Trump did, and he doesn’t appear to scratch an unsatisfied itch for Democrats the way Trump has for the GOP.