RESULTS: Republican Tiffany Shedd takes on incumbent Tom O'Halleran in Arizona's 1st Congressional District

• Rep. Tom O'Halleran faces off against Republican Tiffany Shedd in Arizona's 1st Congressional District.
• See the live coverage and full results from all US House elections.
• Arizona's 1st Congressional District is the eleventh largest district in the country and has more Native American residents than any other congressional district.
• According to the Center for Responsive Politics, O'Halleran currently has over twice as much cash on hand as Shedd.
• Polls started closing at 8 p.m. local time.
• The race will be called as soon as there is sufficient data to make a conclusion.

Democratic Rep. Tom O'Halleran will square off against Republican Tiffany Shedd to represent Arizona's 1st Congressional District.

Polls started closing at 8 p.m. local time.

The candidates

O'Halleran, the incumbent, has been in office since 2017. He previously served as a Republican state senator and state representative for Arizona's 1st state district for seven years. He then switched parties, and ran for the US House of Representatives as a Democrat. O'Halleran is currently chair of the Blue Dog Coalition, a group of Democrats with fiscally conservative ideals.

Shedd, who was born and raised in Arizona, is a small business attorney and firearms instructor. She is running on a platform aligned with President Donald Trump and supports increased border security, protecting the Second Amendment, and is pro-enterprise healthcare.

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The district

Arizona's 1st Congressional District is located on the eastern side of the state and includes the Navajo Nation, the Gila River Indian Community, and the Hopi Reservation. The district is the eleventh-largest congressional district in the country and contains more Native Americans than any other district.

President Donald Trump narrowly carried the district by a margin of one percentage point, 47% to 46%, in the 2016 election as O'Halleran was elected to his first term by a margin of seven percentage points over his GOP opponent. In 2018, Democratic US Senator Kyrsten Sinema won the district by a margin of four points over Republican Martha McSally, according to the Daily Kos.

The money race

According to the Center for Responsive Politics, O'Halleran has raised $3 million, spent $2,5 million, and has around $488,000 in cash on hand as of September 30, while Shedd has raised $1.38 million, spent $1.1 million, and has around $191,000 in cash on hand.

What some of the experts say

The race between O'Halleran and Shedd is rated as "leans Democratic" by The Cook Political Report and "likely Democratic" by Inside Elections and Sabato's Crystal Ball at the University of Virginia Center for Politics.