The chart above shows the results of a new NBC News SurveyMonkey Poll -- done between July 2nd and 16th of a national sample of 5,548 registered Democratic voters, with a 2 point margin of error.
It shows that as the second round of debates approach (on July 30th and 31st), the race is still being dominated by only four candidates out of the 25-candidate field. Those four candidates currently have 71% of the support among Democratic voters.
Will the second round of debates change that? Probably not, but I guess stranger things have happened. There's about 15 candidates who are struggling, and if they don't break out in this next debate, then they probably won't last much longer.