2020Final results
2020 election for Arizona's 1st District
U.S. House · Arizona
Tom O’Halleran (D) won with 51.6% of the vote, defeating Tiffany Shedd (R) by 3.2 points.
Tom O’HalleranDemocrat · winner
51.6%188,469
Tiffany SheddRepublican
48.4%176,709
365,178 votes
Source: MIT Election Data and Science LabUpdated Oct 1, 2026, 10:09 AM ET
The seat over time
D − R margin in this seat's races around 2020
Races before and after
Source: MIT Election Data and Science LabUpdated Oct 1, 2026, 10:09 AM ET
Money in this race
Each line compares the two campaigns on one scale.
Tom O’HalleranTiffany Shedd
$3.4M
Raised by the campaign
$1.7M
$3.4M
Spent by the campaign
$1.7M
$63.1K
Cash on hand
$63.3K
Campaign money: FEC, through Dec 31, 2020.
Source: FEC campaign filingsUpdated Dec 31, 2020