We’ve written about this before, but I wanted to call your attention to it again because the possibility of an Electoral College-popular vote split keeps widening in our forecast. While there’s an outside chance that such a split could benefit Clinton if she wins the exact set of states that form her “firewall,” it’s far more likely to benefit Donald Trump, according to our forecast. Thus, as of early Monday evening, our polls-only model gave Hillary Clinton an 85 percent chance of winning the popular vote but just a 75 percent chance of winning the Electoral College. There’s roughly a 10 percent chance of Trump’s winning the White House while losing the popular vote, in other words.
Polling 101: Should You Trust The Polls In 2020? | FiveThirtyEight
As an illustration of this, we can compare Clinton’s current margins in our polls-only forecast against President Obama’s performance in 2012. Clinton — despite Trump’s recent improvement in the polls — leads by 4.7 percentage points in the national popular vote, a wider margin than Obama’s 3.9-point victory over Mitt Romney in 2012.
But Clinton is performing worse than Obama in 10 of the 12 states that were generally considered swing states in 2012. In some cases, such as Florida and Pennsylvania, the difference is negligible. She’s underperforming Obama substantially, however, in Iowa, Michigan, Ohio and Nevada and to a somewhat lesser extent in Wisconsin and Minnesota. She’s considerably outperforming Obama in Virginia and North Carolina, conversely, but that’s not enough to make up for her losses elsewhere.
|OBAMA MARGIN, 2012||CLINTON POLLS-ONLY MARGIN, 2016|
|National popular vote||+3.9||+4.7|
|Traditional swing states|
|New swing states|
So how is Clinton doing better in the popular vote overall, despite failing to match Obama’s performance in most of these swing states? A lot of it is her strong performance in red states, or at least red states where a significant number of Romney voters were whites with college degrees. Thus, Clinton is putting states such as Arizona into play and — although she’s unlikely to win them — states such as Texas, Georgia and even Utah are liable to be much closer than we’re used to. Texas, in particular, can cause a potential Electoral College-popular vote skew because of its large and growing population. If the Democrat goes from losing Texas by 15 percentage points to losing it by 5 points instead, that produces a net gain of about 0.6 or 0.7 percentage points of the popular vote — larger than the margin by which Al Gore beat George W. Bush in the popular vote in 2000 — without changing the tally in the Electoral College.
Clinton’s also making gains among Hispanic voters, but she may not replicate Obama’s turnout among African-Americans. African-Americans, though, are more likely to be located in swing states than Hispanics are. Roughly half the U.S. Hispanic population is in Texas or California, another state where Clinton is likely to outperform Obama (she currently leads in California by 25 percentage points, while Obama carried the state by 23 points) without getting any additional Electoral College benefit from it.
There’s one big qualification: Our model doesn’t account for any sort of ground game advantage for Clinton in the swing states, other than to the extent that advantage is reflected in the polls. That could make a split a bit less likely than our model infers. Still, Trump’s coalition of white voters without college degrees are overrepresented in swing states, especially in the Midwest, while Clinton’s voters are not.