Election Forecast, State by State

Write Up

How do you predict a general election with Donald Trump?

We can think of a few basic approaches. One of them is to assert that precedent doesn’t apply to this election and that Trump’s case is sui generis. It’s not clear where that leads you, however.

If Trump is “unpredictable,” a phrase we heard used to describe him so often during the primaries, does that mean his chances of defeating Hillary Clinton are 50/50? If that’s what you think, you have the opportunity to make a highly profitable wager. Betting markets put Trump’s chances at only 20 percent to 25 percent instead.

In fact, despite (or perhaps because of) the unusual nature of his candidacy, the conventional wisdom holds that Trump is a fairly substantial underdog. In contrast to 2012, when there were frequent arguments over how solid President Obama’s lead in the polls was, there hasn’t been much of a conflict between “data journalists” and “traditional journalists” on this question of Trump’s chances. Nor has there been one between professionals who cover the campaign and the public; most experts expect Trump to lose, but so do most voters.

But should this seeming consensus give us more confidence — or make us nervous that we’re underestimating Trump again?

Giving Trump a 20 percent or 25 percent chance of becoming president means that Clinton has a 75 percent to 80 percent chance. That might seem generous given that, under ordinary circumstances, the background conditions of this election (no incumbent running and a mediocre economy) would seem to suggest a tossup. Are Clinton’s high odds justified on the basis of the polls? Or do they require making heroic assumptions about Trump, the same ones that got everyone, emphatically including yours truly, in trouble during the primaries?

The short answer is that 20 percent or 25 percent is a pretty reasonable estimate of Trump’s chances based on the polls and other empirical evidence. In fact, that’s quite close to where FiveThirtyEight’s statistical models, which are launching today, have the race. Our polls-only model has Trump with a 19 percent chance of beating Clinton as of early Wednesday afternoon. (The forecasts will continually update as new polls are added.) Our polls-plus model, which considers economic conditions along with the polls, is more optimistic about Trump, giving him a 26 percent chance.

Still, Trump faces longer odds and a bigger polling deficit than John McCain and Mitt Romney did at the same point in their respective races. He needs to look back to 1988 for comfort, when George H.W. Bush overcame a similar deficit against Michael Dukakis to win. Our models are built from data since 1972, so the probabilities we list account for elections such as 1980, 1988 and 1992, when the polls swung fairly wildly, along with others, such as 2004 and 2012, where the polls were quite stable.

If the middling economy is one silver lining for Trump, another is his swing state polls, which don’t seem to be as bad for him as his national polls. They aren’t good by any means, either, but whereas Trump trails Clinton by 6.7 percentage points in our average of national polls, according to our polls-only model, he’s down 4.8 points in our adjusted polling average of Ohio, 5.7 points in Florida, 3.9 points in Iowa, and 2.0 points in Colorado, for instance.

Again, we don’t mean to suggest that these are great numbers for Trump; the Florida result, for example, would represent the worst loss by a Republican there since 1948. Nonetheless, and somewhat in contrast to the conventional wisdom, our model suggests that Trump is more likely to win the Electoral College while losing the popular vote than the other way around. (Though the chances of either scenario are small.)

Some of this may be because we just haven’t had all that much swing state polling; it’s possible we’ll see leads for Clinton in the mid- to high single digits as these states are polled more often. Just this morning, for example, the firm Evolving Strategies published a set of polls in swing states showing Clinton leading Trump by 10 percentage points, on average. If there are more numbers like those, the model will adjust accordingly.

But there’s another potential explanation, which is that Trump is badly underperforming in red states, presumably as a result of having failed to consolidate the Republican base. That may put some traditionally red states into play for Clinton. For instance, Arizona, Missouri, North Carolina and the 2nd Congressional District of Nebraska4 are all tossups, according to the polls-only model. (Polls-plus has Trump narrowly favored in these places.)

Some of these states could be useful to Clinton. Arizona, in particular, could help Clinton put together some winning maps based on Western or heavily Hispanic states, even if she loses much of the industrial Midwest. Others, such as Missouri, are probably more superfluous. They could potentially add to Clinton’s Electoral College margin, but they aren’t likely to be tipping-point states that make the difference between her winning and losing.

That goes doubly for states such as Texas, Utah, Kansas and Alaska, where polls have often shown a single-digit margin for Trump and have occasionally even had Clinton winning. Republicans are used to racking up huge numbers of votes in these states, bolstering their standing in the national popular vote. If Trump wins Texas by only 6 percentage points instead of 16, that will hurt his popular-vote margin without affecting his Electoral College odds much.

Is the reverse also true? Is Trump overperforming in blue states, relative to how a Republican usually does? It depends on where you look. The Northeast was Trump’s strongest region in the primaries, and he’s gotten relatively good numbers — although he still trails Clinton — in polls of New Jersey, Connecticut and Maine. (He also leads Clinton in one poll of Maine’s 2nd Congressional District, which would be worth one electoral vote.5) However, he’s losing by typical margins in New York and California, where he has vowed to compete.

Overall, the polls so far suggest a slightly less polarized electorate and a somewhat wider playing field than we’ve gotten used to in recent years. That’s a potentially refreshing change, although it may prove to be ephemeral as both Clinton and Trump have room to grow with their party bases and could gain ground in traditionally blue and red states as a result.

More background on Silver's polling data and such at the write up.

Quote from: 卐ANUDDA SHOAH卐 on June 29, 2016, 09:02:39 PM

That'll go up once Hillary's indicted.

She won't be, but considering how unlikable she is, and how she's had her best few weeks and he's had his worst, yet he's still close? Yeah, it shouldn't be this close.

It really isn't, if you actually go state by state. Both Clinton and Trump have their usual bastions of support (Northeast and West Coast for Clinton, Montana to Alabama for Trump) - problem is that Trump is underperforming in states that he, as a Republican, should be leading. Places like Georgia and Arizona are within a couple points of a Clinton lead due to minority support, giving her an even greater advantage.