The suburban shift toward the Democrats helps explain why they're about to take control of the House. The graphic below shows the shift — and it shows that even the deep-red rural districts elected Republicans with smaller margins than in 2016.

Why it matters: Races tend to be much closer in the suburbs, and that's where Democrats picked up the most seats. With few exceptions, Democrats in conventionally blue districts won by larger margins than Clinton in 2016 and Republicans won by slimmer margins than Trump in 2016.

How to read this chart: A CityLab data project categorized every U.S. House district by the density of its neighborhoods. By comparing the margin victory for Hillary Clinton or Donald Trump in 2016 to the vote margin in the 2018 midterms, we can see which districts shifted to the left or right by comparison.

  • Districts with higher Democratic or lower Republican margins point left; those with smaller Democratic or higher Republican margins point right. The color of each arrow shows who won the district in 2018.
Expand chart
Note: This chart includes only the 393 districts where both a Republican and Democrat ran in 2018. Data: CityLab and Associated Press; Chart: Chris Canipe/Axios

Go deeper

The cliffhanger could be ... Georgia

Illustration: Sarah Grillo/Axios

It hasn't backed a Democrat for president since 1992, but Georgia's changing demographics may prove pivotal this year — not only to Trump v. Biden, but also to whether Democrats take control of the Senate.

Why it matters: If the fate of the Senate did hinge on Georgia, it might be January before we know the outcome. Meanwhile, voters' understanding of this power in the final days of the election could juice turnout enough to impact presidential results.

Amy Harder, author of Generate
6 hours ago - Energy & Environment

Climate change goes mainstream in presidential debate

Photo illustration: Aïda Amer/Axios. Photo: Olivier Douliery-Pool/Getty

The most notable part of Thursday’s presidential debate on climate change was the fact it was included as a topic and assumed as a fact.

The big picture: This is the first time in U.S. presidential history that climate change was a featured issue at a debate. It signals how the problem has become part of the fabric of our society. More extreme weather, like the wildfires ravaging Colorado, is pushing the topic to the front-burner.

Finally, a real debate

Photo: Morry Gash/AP

A more disciplined President Trump held back from the rowdy interruptions at tonight's debate in Nashville, while making some assertions so outlandish that Joe Biden chuckled and even closed his eyes. A Trump campaign adviser told Axios: "He finally listened." 

The result: A real debate.