National polls have shown Hillary Clinton's lead over Donald Trump tightening over the past month. According to the Huffington Post Pollster average, Clinton's advantage has dropped from a relative landslide of 8 points to a more modest 4 points, more similar to Barack Obama's re-election victory in 2012 than his first win in 2008. This narrowing has prompted concern among many observers, but it fails to account for one simple thing: There is, of course, no national election in the U.S., but instead 51 separate contests in the states and the District of Columbia. And during this same period, the polls have given Clinton a much clearer edge in the all-important Electoral College.
This is no surprise. Donald Trump is not a traditional candidate running a traditional campaign. He has largely relied on free media coverage rather than typical campaign strategies like running TV ads. He has invested astonishingly few resources into building a field operation to help get his voters to the polls, or even a data operation to know which voters to target at all. Hillary Clinton, on the other hand, has assembled a top-notch organization that has dominated the airwaves and taken data analysis to a level even beyond the impressive achievements of the Obama campaign. Never before in the modern era has there been such a disparity in campaign strength between two presidential candidates.
Political scientists have shown that many so-called "campaign effects"—in other words, the practical impact that traditional campaign activities have on the electorate—often cancel each other out, because opposing candidates typically make comparable investments in their campaigns. However, this year we are likely to see a wide gulf in the impact of each candidate's campaign. One scholar has estimated that Trump's non-campaign could cost him 6 percent nationally. In our polarized era, where no presidential candidate has won by double digits in three decades, that could make a staggering difference.
Since candidates only invest time and money in swing states, all the campaign effects from TV ads or get-out-the-vote operations will be concentrated in a tiny battleground of fewer than a dozen states. That means that if there is a large difference in campaign effects between Clinton and Trump, we won't see its impact nationally like we would in the swing states themselves. So far, that's just how things seem to be playing out.
Clinton's national polling lead might be comparable to Obama's in 2012, but the Electoral College map points to a race that simply isn't that close. Clinton has a dominant edge in enough states for a majority of electoral votes and isn't even running ads in the key swing states of Colorado and Virginia because she feels her leads there are so solid. (These were states George Bush easily won just over a decade ago.) She also has made major investments in North Carolina, which Mitt Romney carried, and even has her toes in the water in genuine red states like Arizona and Georgia, suggesting possible increased investment closer to November.
In both 2008 and 2012, if you lined up every state according to the size of the margin between Obama and his Republican opponents, the state that put Obama over the top—that is, gave him 270 electoral votes—both times provided him with a wider margin than he earned nationally. In other words, Obama performed better in the crucial swing states than he did nationwide, and according to the polls, the same is true for Clinton today.
And that's really all that matters. Even if the race were to narrow several points more on a national basis, Clinton's swing-state advantage would keep her on the good side of 270. This isn't to say that the Electoral College has a built-in bias in favor of Democrats: After all, four elections ago, Republicans won an electoral vote majority despite losing the popular vote. Rather, Clinton's edge in the battleground states is attributable to her far superior campaign—and Trump's stunning lack thereof.
It's certainly an unusual situation, because in previous eras, when the field of states in play was far bigger, there was less of a difference between the national picture and what was going on in the swing states. But these days, with such a small group of states up for grabs, the disparity is magnified. That has the effect of masking Clinton's lead where it counts, and with Trump woefully behind in campaign preparedness, he's just about out of time to try to make up the gap.