Current statewide margin
The presidential race in Arizona remained too close to call on Monday evening, but Joseph R. Biden Jr. held a lead in the state’s biggest city. Phoenix and its suburbs swung to the left, making it possible that Mr. Biden wins Arizona, even as other areas shifted to President Trump.
Maricopa County comprises 60 percent of the state’s voters and is home to Phoenix. Mr. Trump narrowly won the county in 2016, and support for Republicans has slipped there in recent elections. Voters there supported Kyrsten Sinema, a Democrat, in the 2018 Senate race.
Margin of victory in Arizona counties since 2008
Each line shows margins in one county over time
Within Maricopa County, Mr. Biden won in most precincts with a majority Hispanic population. In several areas of other swing states, the Hispanic vote notably went the other way.
Mr. Biden also won in many precincts that skewed younger.
The shift to the left in Maricopa County has helped put Mr. Biden ahead statewide. His reportedly strong support among Native Americans in the state has also been a benefit.
Still, as of Monday evening, Mr. Biden led by only about half a percentage point. A Democratic candidate for president has not won Arizona since Bill Clinton in 1996 — and he was the first Democrat to win there since Harry S. Truman in 1948.