2020 South Carolina Primary: Final Polling Update

From 7 am to 7 pm EST on February 29, 2020, polls will be open in South Carolina for that state’s Democratic presidential primary. This election follows similar contests in Iowa and New Hampshire in which United States Senator (“Senator”) from Vermont Bernie Sanders and former South Bend, Indiana Mayor Pete Buttigieg fared very well, and a strong win by Sanders in the Nevada Caucuses–where former Vice President Joe Biden finished a strong second. Unlike those three states, though, the Democratic primary electorate in South Carolina is expected to be majority-black; three in five (61%) 2016 South Carolina Democratic Primary voters were black, as were 55% in 2008. This is also the final early nomination-related election in which former New York City Mayor Michael Bloomberg will not appear on the ballot.

To learn how I calculate candidate WAPA (weighted-adjusted polling average), please see here. Here is my updated weighting scheme:

  • Polls conducted entirely or partially after February 3, 2020, but before February 12, 2020 are weighted 2.00 or 1.00+fraction[1] times, respectively, higher than polls conducted entirely before February 4, 2020.
  • Polls conducted entirely or partially after February 11, 2020, but before February 23, 2020 are weighted 3.00 or 2.00+fraction times, respectively, higher than polls conducted entirely before February 12, 2020.
  • Polls conducted entirely or partially after February 22, 2020, but before March 1, 2020 are weighted 4.00 or 3.00+fraction times, respectively, higher than polls conducted entirely before February 23, 2020.

I have only been to South Carolina once, driving through it one March 1990 day as part of an epic round-trip road trip between Boston, Massachusetts and Atlanta, Georgia. I have no photographs from that trip, however, so here is one I took in Concord, Massachusetts in October 2008 of trees mimicking a traffic light.

Traffic light trees 2 10-12-2008


Here is a breakdown of publicly-available South Carolina Primary polls as of midnight EST on February 29, 2020:

  • 53 since January 1, 2019
  • 41 since the 1st Democratic debate on June 26, 2019
  • 22 since the 5th Democratic debate on November 19, 2019
  • 18 since the 7th Democratic debate on January 14, 2020
  • 15 since the Iowa Caucuses on February 3, 2020
    • 7 between February 12 and February 22
    • 8 beginning February 23

Table 1: Final South Carolina WAPA for declared 2020 Democratic presidential nomination candidates

Candidate All Polls Since 1st Debate Since 5th Debate Since 7th Debate Since


Biden 33.2 33.0 32.4 32.2 32.3
Sanders 18.6 18.7 20.3 20.7 20.7
Steyer 11.4 11.7 13.4 13.5 13.5
Warren 9.1 9.1 8.4 8.1 8.1
Buttigieg 7.7 7.7 8.5 8.7 8.8
Klobuchar 3.9 4.0 4.6 4.8 4.9
Gabbard 2.1 2.2 2.5 2.6 2.4
Bloomberg 0.3 0.3 0.3 0.2 0.2
DK/Other 13.7 13.3 9.6 9.1 9.1

Other than a slight uptick for Sanders and billionaire activist Tom Steyer—and an unsurprising reduction in the percentage either undecided or choosing an unlisted candidate—it is difficult to discern momentum in either direction for any candidate in Table 1. Biden has consistently led polls of the South Carolina Primary, hovering in the 32-34% range on average, with Sanders in second place at 18-21%. If these numbers are predictive, only Biden, Sanders and (possibly) Steyer seem poised to crack the 15% statewide threshold to be awarded pledged delegates to the Democratic National Convention this July; depending on how their support is distributed geographically, Massachusetts Senator Elizabeth Warren and Buttigieg could accrue some delegates in one or more Congressional districts.

However, the percentages calculated since the Iowa Democratic Caucuses on February 3 mask a substantial shift in support following the Nevada Democratic Caucuses on February 22 (Table 2).

Table 2: South Carolina WAPA for declared 2020 Democratic presidential nomination candidates following the Iowa Democratic Caucuses

Candidate Before Nevada Caucuses After Nevada Caucuses Change
Biden 26.0 36.5 +10.5
Sanders 21.2 20.6 -0.6
Steyer 15.7 12.9 -2.8
Warren 8.7 7.7 -1.0
Buttigieg 9.5 8.3 -1.2
Klobuchar 5.7 4.0 -1.8
Gabbard 2.1 2.2 +0.1
Bloomberg 0.7 0.0 -0.7
DK/Other 10.5 7.8 -2.7

After finishing 4th and 5th in the Iowa Caucuses and New Hampshire Primary, respectively, Biden appeared to be teetering on the edge of irrelevance, falling behind Sanders in my overall WAPA for the first time (data not shown). But his strong second-place finish in the Nevada Caucuses may have been just what Biden needed: his standing has soared more than 10 percentage points (“points”) in the South Carolina Primary since then. The percentage undecided or naming other candidates has dropped nearly three points over the same time span; Biden could well be picking up support from these late-deciders. At the same time, drops in support of between 1.2 and 2.8 points were registered by Steyer, Minnesota Senator Amy Klobuchar and Buttigieg .

One slight note of caution: using FiveThirtyEight.com’s pollster ratings, the eight pollsters assessing South Carolina Democratic voters before the Nevada Caucuses had a B average, while the seven pollsters in the field afterward had a B- average. Still, if this late shift in support in Biden is real—and it continues as voters make up their minds—Biden could earn 40% of the vote on Saturday, with Sanders the only other candidate to top 20%. The question then would be whether any other candidates accrue any delegates.

We shall see.

Until next time…

[1] Percentage of days the poll was being conducted were after the most recent primary or caucuses

2 thoughts on “2020 South Carolina Primary: Final Polling Update

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