In two previous articles (here and here) I looked at how the polls for the Democratic nominee for President compared to the bookmakers’ odds. This is an update to see how things have changed in the last two months as we approach the Iowa caucuses (February 3).

A snapshot taken of the polls and odds on four dates presents a good summary of what has happened: (i) August 15, when Elizabeth Warren’s odds first passed Joe Biden’s, (ii) October 13, when Warren’s odds peaked, (iii) November 20, around my last report, and (iv) January 24, the most recent data when this article was written. All data are taken from averages compiled by RealClearPolitics.com.

First, the poll numbers, in %:

Aug. 15 Oct. 13 Nov. 20 Jan. 24
Biden 30.5 29.4 30.7 28.9
Warren 17.3 23.2 18.0 14.6
Sanders 16.0 16.6 16.7 22.7
Harris 8.0 5.0 4.3
Buttigieg 5.2 4.4 8.0 7.4
Booker 2.0 1.6 1.3
Yang 1.5 2.6 2.3 4.0
Bloomberg 3.0 7.6
Gabbard 1.0 1.3 2.0 1.4
Klobuchar 1.4 1.5 1.7 3.6
Steyer 1.4 1.0 2.1

 

Next, the odds, in % (anyone who has never been above about 5% not shown):

 

Aug. 15 Oct. 13 Nov. 20 Jan. 24
Warren 29.6 53.4 26.8 11.3
Biden 27.9 19.9 25.5 35.6
Harris 16.6 4.5 2.2
Sanders 14.1 6.3 15.7 33.6
Buttigieg 8.6 7.7 20.5 7.2
Yang 5.0 5.9 5.6 4.5
Clinton 2.5 8.7 7.0 4.5
Bloomberg 4.9 12.5

(Note: the odds add up to more than 100% since these are inferred from betting odds, which have a vig for the bookies cooked in.)

We see that the poll numbers are much more stable, especially for Biden. Warren had a small rise, mostly at the expense of Harris, only to give it all back (and then some) as Buttigieg gained ground and Bloomberg entered the race. Sanders has gained some ground recently.

The odds are much more volatile: Warren had a huge surge, taking favor from the next four contenders. Clinton (Hillary, that is) and Yang were the only others to gain traction in October. (Of course, as I mentioned in the last article, Clinton is not in the polls data since she has not declared.) Since her peak, Warren gave it all back by November as Biden and Sanders recovered and Buttigieg surged into third place. Since then, Warren’s support has continued to erode and Buttigieg gave back all his gains, with Biden, Sanders, and Bloomberg being the beneficiaries. Bloomberg has actually surpassed Warren in the odds; he had reached 8.9% in the polls right after declaring, but dropped back and is just now getting back to that level.

It will be interesting to see what happens in the Iowa caucuses. According to RealClearPolitics.com, the polls for Iowa now have (and have for several months) basically a four-horse race: Biden (20.0%), Sanders (19.3%), Buttigieg (16.8%), and Warren (16.3%). Just to show how tight and ever-changing these are, in November we had the same top four with about the same spread from first to fourth, but Buttigieg was on top and Biden in fourth. Of course, they are all more or less within the margin of error, so that is not surprising. Klobuchar (8.3%) is in fifth, with Yang (3.5%) and Steyer (3.3%) constituting a third tier.

I live in Iowa, and my unscientific impression from seeing yard signs is that Warren and Buttigieg are much stronger than Biden and Sanders, and Yang is a good bet as a dark horse. But maybe they just have better teams on the ground in my area. (There are three Warren signs within sight of our house, which is rather depressing.) As I mentioned last time, Steyer is blanketing us with ads, but doesn’t seem to be getting much traction.

There is much more detail at RealClearPolitics.com, if you want the complete picture — they have really nice graphs over time, and give poll results for Iowa, New Hampshire, Nevada and South Carolina, in addition to the national numbers.