Hillary Clinton Has a 76 Percent Chance to Win the Presidency
I think what is important to state here is that this is only true today. So, if the election were held today she could have a 76% chance of winning. However, any single or multiple event or events could change this too. So, don't hold your breath there are still a lot of days until November and the elections.
For now, at least, Hillary Clinton has a 76 percent chance of defeating Donald Trump to become president of the United States.
A victory by Mr. Trump remains quite possible: Mrs. Clinton’s chance of losing is about the same probability that an N.B.A. player will miss a free throw.
Our
model suggests Mrs. Clinton is a strong favorite in 15 states, enough
to give her 186 of the 270 electoral votes she needs to win the White
House. Add to this eight states that polls currently show are leaning
Democratic — including Minnesota, Michigan and Pennsylvania — and Mrs.
Clinton would have 275 electoral votes and the presidency.
But,
with 16 weeks remaining in the campaign, a lot can change. Using the
same model, we would have said that Bill Clinton had less than a 20
percent chance to win the presidency with roughly four months to go in
1992. It was only after Ross Perot left the race and the Democrats
rallied around Mr. Clinton after the Democratic convention that his
polls improved. And they improved sharply. One month later, he was an 84
percent favorite.
This
kind of polling volatility should be expected, particularly with party
conventions at hand. It is one reason that Mrs. Clinton’s probability of
victory is not higher. Current polling averages suggest a four-point
victory in the national popular vote for Mrs. Clinton, if nothing
changes. But we expect changes between now and Election Day.
The
Upshot is not the only news organization trying to forecast election
results. We believe each model provides useful glimpses of possible
futures, so we are compiling forecasts from a variety of them into one
easy-to-digest table.
Viewed
side by side, the differences among the models become clearer. Arizona,
for example, is rated as a tossup by FiveThirtyEight, while our model
has not yet seen enough polling evidence to revise its assessment of
Arizona’s recent history as a Republican-leaning state. Similarly, while
the betting markets rate New Mexico as almost a sure thing in the
Democratic column, our model is not as certain, giving Mr. Trump a 21
percent chance to upset Mrs. Clinton there.
We’ll update our forecast every day until Election Day. Check here to see our predictions
and that of others, and to play around with the possible paths that
could lead Mrs. Clinton or Mr. Trump to victory. Below is more about how
we built our model.
This
is by design. Our model starts with a weighted average of polls in each
state, giving polls conducted more recently and polls with a larger
sample size a greater weight in the average. At this point in the
election cycle, it uses a longer time window to calculate these
averages. This steadiness means it is more stable and less inclined to
chase after the most recent poll. But it also means it is slower to
react to developing trends, such as recent polling that may indicate a
tightening race. This can be a feature or a bug, depending on your
perspective. Preconvention polls are informative, but history suggests
that it is a mistake to place too much emphasis on a week’s worth of
polling.
Let’s
say you want to forecast the average margin of national polls for the
next month. Would you rather take the average of the polls from the
previous two weeks or average every poll from the previous two months?
More often than not, you’d be better off taking the average of the
longer period. This informs the approach taken by our model.
That
said, we expect the simulations in our model to converge rapidly over
the next month or two, as the conventions end and polling becomes more
predictive of the final outcome.
Distributions are more interesting than averages.
Our estimate for Mrs. Clinton’s lead over Mr. Trump nationally is 3.7 points; our friends at FiveThirtyEight have a slightly smaller estimate of 3.4 points,
but our overall probabilities of winning differ by 12 percentage
points. This is a small difference, but a notable one. We believe one
source of the difference is in the ways we believe states will (or
won’t) swing together, and how much they’ll shift.
This
is illustrated best by seeing our electoral distributions side by side:
The FiveThirtyEight histogram is wider and flatter than ours. It
assigns a greater chance that something highly unusual will happen,
while ours thinks that the course of this election will look pretty much
like the ones that have come before it. For example, we think there is
only about a 1 percent chance that Mrs. Clinton will get fewer than 160
electoral votes. The FiveThirtyEight model assigns that prospect an 8
percent chance.
The distribution of electoral votes in the Upshot’s
forecasting model is taller and more narrow than FiveThirtyEight’s,
leading to a higher estimated win probability for the Democrats.
New York Times
Electoral votes for Hillary Clinton →
FiveThirtyEight
Electoral votes for Hillary Clinton →
Fundamentals say it’s a good year for Mr. Trump, but we don’t rely much on fundamentals.
Although
our model uses how states voted in previous presidential elections as a
starting point, it is almost entirely a polls-based model.
In
contrast, some other models of presidential elections use so-called
fundamentals to arrive at their forecasts, like the state of the economy
and the number of years the Democrats have been in power. These
fundamentals models will generally be more favorable to Mr. Trump;
history suggests that this should be a more Republican-favoring election
cycle. For example, the FiveThirtyEight “polls-plus” model has been more favorable to Mr. Trump than the “polls-only” model.
Our model is well calibrated.
One
of the differences between a model and a simpler polling average is
that the model knows how wrong it has been in the past. So when we say
that we think Mrs. Clinton has a 14 percent chance of winning North
Dakota, we mean that, judging from how the polling averages have moved
in previous election cycles, candidates in Mrs. Clinton’s position have
won in one in seven similar situations in past elections.
Of
course, there is no guarantee that this election will turn out the way
that elections have in the past, a flaw that is common to any
forecasting model. These numbers are our best guesses using the
information we have.
Expect shifts.
This has been a long election cycle, but the ride will probably get even more wild. Our forecast will move; again, here’s where you can find it.
The Upshot provides news, analysis and graphics about politics, policy and everyday life. Follow us on Facebook and Twitter. Sign up for our newsletter.
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