On Friday, FiveThirtyEight and Morning Consult released the first poll assessing the Democratic presidential candidates following the first round of debates, which took place on Wednesday and Thursday.

While there are numerous interesting findings in the data, a few stand out from the rest.

Prior to the first debate, former Vice President Joe Biden led the pack with 41.5% of the vote. After the first debate (in which he didn’t even participate), his support shifted downward, landing at 35.4%. Following the second debate in which he is widely believed to have been routed, his support dropped again to 31.5%.

  • Total differential: -10%

Sen. Kamala Harris (D-CA), on the other hand, had the largest positive jump. Before the first debate, she stood at 7.9% support. After the first debate (in which she didn’t participate), support for Harris dropped to 6.3%. However, after her performance in the second debate, which is widely considered masterful, Harris’ support more than doubled to 16.6%.

According to the info-graphic provided by FiveThirtyEight, most of Harris’ newly acquired support was siphoned from Biden and Sen. Elizabeth Warren (D-MA).

  • Total differential: +8.7% (+10.3% if measured after her initial dip)

The poll also asked about candidate favorability before and after the debates. Biden’s favorability fell by less than one percentage point (76.5% to 75.6%), while his unfavorabiltiy increased by 3% (16.1% to 19.1%).

Harris climbed from 56.2% favorability to 66.9%, while her unfavorability only increased by 1.5% (11.3% to 12.8%).

Many of the other Democratic candidates shared a strikingly similar narrative – a bump or a dip following the first debate, then a reversal after the second.


Aside from Harris, in the winners’ circle are Sens. Elizabeth Warren (D-MA), Bernie Sanders (I-VT), and, to a lesser extent, former HUD Secretary Julian Castro.

Sen. Elizabeth Warren saw her stock rise from 12.6% before the first debate to 18% after, only to fall back down to 14.4% following the second debate. As a result, Warren’s differential stands at a fairly paltry +1.8%.

The FiveThirtyEight info-graphic reveals that much of Warren’s boost in support following the first debate was siphoned from Bernie Sanders, Kamala Harris, and Mayor Pete Buttigieg. Warren’s subsequent loss, however, went almost entirely to Harris.

Warren’s favorability increased by 8% (63.4% to 71.4%). Her unfavorability decreased by 1% (13.5% to 12.5%)

Sen. Bernie Sanders garnered support following both debates. After the first debate (in which he did not participate), Sanders’ support went from 14.4% to 16.4%. Following his performance in the second debate, he gained almost another percentage point, rising to 17.3%, for a total differential of +2.9%.

Sanders took some of Biden’s support, but gave much of it back, then sucked up support from several B-level candidates.

Sanders’ favorability increased by 2% (74.3% to 76.3%), and, in a trait shared only by Elizabeth Warren, his unfavorability actually decreased by 0.1% (17.6% to 17.5%).

Julian Castro, who began with 0.7% support before jumping to 2.1% after his performance in the first debate, dropped down to 1.7% after the second debate (in which he did not participate). This may seem like nothing, but it’s a 142% increase in support for a candidate with little name ID.

Castro’s favorability rose by 18.5% (29.3% to 47.8%), the most of any candidate over the two debates. His unfavorability increased by just 2.4% (9.3% to 11.7%).


Aside from Biden, in the losers’ circle are Mayor Pete Buttigieg, Sen. Cory Booker (D-NJ), and former Rep. Beto O’Rourke.

Buttigieg, who began with 6.7% support, ended the debates with just 4.8%. His supporters fled to Elizabeth Warren and Kamala Harris. That said, Buttigieg’s favorability did increase by 9.4%, while his unfavorability increased by only 3.8%.

Booker lost 0.2% support, moving from 3% to 2.8% after all was said and done. The senator’s support was primarily siphoned by three candidates – Sanders, Harris, and Biden. His favorability rose by 9.9%, while his unfavorability rose by 1.9%.

O’Rourke, who came into the debates with 3.6% support, left with just 2.2%. His losses came mostly at the hands of Joe Biden. The former representative saw his favorability increase by just 2.4%, while his unfavorability increased by 6.7%.


Harris is the clear victor of this first round of debates, while Biden is the definitive loser. Despite a well-regraded performance, media darling Pete Buttigieg seems to be slipping. Booker, who some believed would be a frontrunner prior to the race, simply doesn’t seem to be catching on. Sanders and Warren, while liked, mainly coasted, failing to move the meter a great deal. Julian Castro, while still a B-level candidate, saw some serious gains that could portend greater things to come.

It’s difficult to compare this race to the 2016 Republican primary because that year was such an outlier. According to RealClearPolitics, of the 87 polls taken after the first Republican debate until the nomination was locked up, Trump was ahead in all but five – and usually by substantial margins.

The Democrats, on the other hand, have at least ten viable candidates, any one of whom could break out and become a star, or break down and burn out over the course of the 12 debates.

In an August 2015 poll from CNN, Trump commanded 24% support, while Jeb Bush held 13%. At the time, Sen. Ted Cruz (R-TX) had only 4% support, while Ohio Governor John Kasich had 5%. These two men (Cruz, Kasich) would wind up as the last standing against Trump.

At the time of the final poll cited by RCP in May 2016, Trump had drummed up 49% support, but Cruz had risen to 25%, and John Kasich to 19%. If one of the men had dropped out, Trump would likely have had a serious rival for the nomination.

All of this is to say that in this wonky mess, it must be remembered that this was just one of 12 scheduled debates that will stretch into 2020. This is a snapshot of the moment, and in 2019, when social media and 24-hour news dominate the political conversation, the winds can shift in an instant.

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