Since Polly first started her Super Tuesday examinations, her forecasts have been influenced by two significant developments:
- Pete Buttigieg dropped out and endorsed Joe Biden
- Amy Klobuchar dropped out and endorsed Joe Biden
These changes had an impact on Polly’s original forecast. First, Klobuchar was expected to win in Minnesota, so the Minnesota election will be very different now from what was first projected. Second, when a candidate drops out without an endorsement, Polly allocates votes based on their supporter’s second choice. When there is an endorsement, Polly considers the impact if some of the supporters abandon their second choice and vote according to the endorsement.
Here is a brief rundown of how these events have altered Polly’s forecast:
- California: little has changed: Sanders is still forecast to win the state, Biden is now a clear second place.
- Maine: Polly was already forecasting Biden to win Maine. With these developments, Biden’s victory is even stronger.
- Massachusetts: Warren is now forecast to come in third, behind Biden and Sanders. Sanders is still forecast to win.
- North Carolina: This is the biggest change: previously Sanders was forecast to win; now Biden is favored to win.
- Texas: Sanders is still forecast to win Texas, but Biden is within the margin of error. Texas could go Biden in a close race.
- Colorado: Sanders is still forecast to win. There is now a 3-way race between Biden, Bloomberg, and Warren for second place.
- Virginia: has too high a margin of error for a forecast.
- Minnesota: Biden is forecast to win with Sanders taking second.
Klobuchar dropping out and endorsing Biden greatly changes the landscape in her home state of Minnesota, whereas previously Polly saw her leading with 30% of the vote. There are now two ways a supporter of Klobuchar or Buttigieg could react: take the endorsement and vote for Biden or ignore the endorsement and vote for their second-choice candidate.
If, for instance, all of Klobuchar’s supporters voted for their second choice, about a third of her Minnesota supporters would choose Biden while only 20% would support Sanders. This isn’t enough to win Minnesota for Biden; under this scenario Sanders still wins by 10 points.
On the other hand, if Klobuchar’s endorsement does persuade some of Sanders’ supporters to vote for Biden. Polly estimates that Biden could pick up an additional 2% of Minnesota voters over those that he received from Klobuchar, winning Minnesota in a landslide 42%.
What is the most likely scenario? Some people will vote their second choice, and some will vote the endorsement; Polly forecasts that Minnesota will be close, and that Biden will prevail based on the strength of Klobuchar’s endorsement.