All of these charts reflect the results of the new Quinnipiac University Poll -- done May 16th and 20th of a national sample of 1,078 voters (including 454 Democrats and Democratic leaners). The margin of error for voters is 3.7 points, and for Democrats/Leaners is 5.6 points.
The chart above shows the current level of support each Democratic candidates has among Democrats and Leaners. Joe Biden continues to lead all others candidates with 35% -- registering more than twice the support of second place finisher, Bernie Sanders (16%). Elizabeth Warren has moved up into third place with 13%. They are the only candidates in double-digits.
The charts below show the favorable/unfavorable rating of each candidate. The first chart (with blue bars) shows the opinion of Democrats and Leaners. The second chart (with purple bars) shows the opinion of all voters.