15-SECOND TAKEAWAY
Biden 334 (21 Leaners) | 80 Tossups | Trump 124 (18 Leaners)
270 Threshold: WI (60 Likely D)
Hot Contests: AR, SC, TX, GA, IA, OH, NC, NV
August Ends with a nudge to the Blue
As reported Sunday, Florida and North Carolina took an August vacation one shade to the right. Their sojourn didn’t last long though. Just the last three days, polls came out showing them back to where they were at the beginning of the month. FL is Likely D and NC Leans D.
Moving with them is Arizona, from Leans D to Likely D for the first time. Fox News puts Biden up 9% (LV) and 10% (RV) in AZ and up 4% (RV and LV) in NC.
TX Texas threatens to move from Tossup to Baby Pink, but a pair of Morning Consult polls in early and late August both came up just 1 point short of that for Trump. Tossup
GA Georgia was confirmed a Tossup by several August polls.
WI, MI, PA Trump’s 3 rust belt states were confirmed Likely D in several polls.
NV was polled for the first time in 4 months. Once again, Biden came in with a lead just over the margin of error. Leans D
BACKGROUND
To see recent polling developments in the state Electoral races, look at some of my other reports: 8/14 334 to 124, 7/29 320 to 125, 7/3 350 to 126, 6/25 350 to 126.
For those of you who haven’t followed my reports, here’s a brief explanation of how I categorize the state of each state race. It’s a snapshot, not a prediction!
A word on my analysis methods…
I take all polls I can find from 270ToWin or 538 for the latest month polled, omitting any pollsters that have a noticeable bias (like Trafalgar, Spry, Gravis, or Rasmussen). To avoid a simple average without working a weighted average, I categorize each poll and then take the median of them to get a predominant category.
Stale states will stay in the same category until new polling comes in.
I categorize leads by this arbitrary set of rules:
My definition of a Tossup is a lead of +/- ½ margin of error (MOE). That means the leader has less than a 60% chance of truly leading. See Fig. 1 below.
I define Leaner as between ½ and 3/2 of the MOE, so the reported leader has between 59.9% and 77% chances of actually leading. See Figs. 1 & 2 below.
My Likely category is between 3/2 and 3 * MOE, so the leader has between 77% and 93% chance of being ahead.
My Safe category is only for leads at least thrice the MOE, so the leader has a greater than 93% chance of being ahead.
I am not doing any predicting, just blending any and all polls within the last month (or last month taken — if the last poll was in April and it’s now June, I’ll take the month of April) rated B/C or better by 538.
This is intended to give a snapshot of the horse race. Nothing more.
Figure 1. Lead = ½ the margin of error. Leader polls 48%, Trailer 46%, MOE 4%. Assume normal distribution and Trailer increases exactly match Leader decreases (undecided is constant). Probability of Leader really leading is the probability that his true percentage is 47 or higher (hence, the probability that the Trailer’s true chance is 47 or lower). From the graph, Prob = 59.87%
Figure 2. Lead = 1.5 x the margin of error. Leader polls 48%, Trailer polls 42%, MOE 4%. Assume normal distribution and Trailer increases exactly match Leader decreases (undecided is constant). Probability of Leader really leading is the probability that his true percentage is 45 or higher (hence, the probability that the Trailer’s true chance is 45 or lower). From the graph, Prob = 77.34%
Try out this and other scenarios at onlinestatbook.com/…
