Democrat Ann Kirkpatrick has beaten Lea Marquez Peterson, a Republican, in the race for the House seat representing Arizona's 2nd Congressional District, currently held by Republican Martha McSally.
With all precincts reporting, Kirkpatrick has 54.7 percent of the vote, followed by Marquez Peterson with 45.3 percent.
McSally has represented the district in the House since 2015.
Democrats have gained a majority in the House, with 234 seats in the next Congress. All of Arizona's House seats have been decided; one switched hands, going to Democrats.
The number of votes cast for Democrats in House races has increased 53.5 percent from the 2014 midterms, compared with an increase of 24.9 percent for Republicans.
The district went for Democrat Hillary Clinton in 2016 by a margin of 4.8 points. President Trump, a Republican, won Arizona by 3.5 points.
Data is from the Associated Press. This story may be updated if more information becomes available. It is powered by Heliograf, The Post's artificial intelligence system.