2016 United States presidential election in Arizona

The 2016 United States presidential election in Arizona was held on Tuesday, November 8, 2016, as part of the 2016 United States presidential elections in which all 50 states plus the District of Columbia participated. Arizona voters chose electors to represent them in the Electoral College via a popular vote, pitting the Republican Party's nominee, businessman Donald Trump, and running mate Indiana Governor Mike Pence against Democratic Party nominee, former Secretary of State Hillary Clinton, and her running mate Virginia Senator Tim Kaine. Arizona has 11 electoral votes in the Electoral College.

Despite the country at-large swinging to the right, Arizona's Republican margin of victory decreased from 9.0% in 2012 to only 3.5% in 2016, thus making it one of 11 states (along with the District of Columbia) to do so. Trump's margin of victory in Arizona was the smallest for any Republican who won the presidency since Arizona's founding in 1912, with Calvin Coolidge's 5.8% victory in 1924 being the second closest.

Notably, Maricopa County, the state's most populous county, went more Democratic than the state as a whole for the first time in state history. The county had not voted for a Democrat since Harry S. Truman in 1948. Therefore, Trump's narrow win in the county suggested the Republican Party was losing ground in the state. In fact, the county and the state would go on to vote Democratic in 2020.

Democratic primary
Six candidates appeared on the Democratic presidential primary ballot:
 * Bernie Sanders
 * Hillary Clinton
 * Rocky De La Fuente
 * Martin O'Malley (withdrawn)
 * Henry Hewes
 * Michael Steinberg

Results

 * Detailed results per congressional district

Republican primary
Fourteen candidates appeared on the Republican presidential primary ballot:
 * Jeb Bush (withdrawn)
 * Ben Carson (withdrawn)
 * Chris Christie (withdrawn)
 * Ted Cruz
 * Carly Fiorina (withdrawn)
 * Lindsey Graham (withdrawn)
 * Mike Huckabee (withdrawn)
 * John Kasich
 * George Pataki (withdrawn)
 * Rand Paul (withdrawn)
 * Marco Rubio (withdrawn)
 * Rick Santorum (withdrawn)
 * Tim Cook
 * Donald Trump

Green primary
The Arizona Green Party held its primary on March 22. Jill Stein won with 82% of the vote, and the overall number of voters that took place in the primary saw an increase from 561 in 2012 to 770 in 2016. Only two candidates qualified for the primary:

Polling
The first poll conducted in March 2016 showed a tie between Clinton and Trump. From March 2016 to October, the polling in this normally Republican state was quite close, with neither candidate seriously leading. In late October, Trump gained momentum and won every pre-election poll in the weeks leading up to the election. The final poll showed Trump leading Clinton 46% to 41% and the average of the final 3 polls showed Trump leading 47% to 43%, which was accurate compared to the results.

Predictions
The following are final 2016 predictions from various organizations for Arizona as of Election Day.

By congressional district
Trump won 5 of 9 congressional districts. Both candidates won a district held by the other party.

Turnout
Voter Turnout was 74.2% with 2,661,497 ballots cast out of 3,588,466 voters.

Analysis
Donald Trump won Arizona with a margin of 3.5%, a reduced margin from Mitt Romney's 9.0% margin in 2012. Arizona was among the eleven states in which Hillary Clinton outperformed Barack Obama's margin in 2012, primarily due to an increase in Hispanic voter turnout in southern Arizona, including heavily populated Maricopa County. This was the weakest performance for a Republican in the state since 1992. Trump also lost the 2nd congressional district that Romney had won four years earlier.

Maricopa County in particular went from a 10.7% margin of victory for Romney in 2012 to a 2.8% margin of victory for Trump, making this only one of three times that a Democrat held the county's margins to single digits since 1952. Indeed, the only other times were 1964 and 1996. Clinton also came the closest of any Democrat to winning Yuma County since La Paz County broke off from it in the 1980s, as the county was last carried by a Democrat in 1964.

Other rural counties that Bill Clinton had won in the 1990s continued to trend in a Republican direction, namely the formerly union-heavy Gila, Graham, and Greenlee counties. In terms of percentage of the vote, Trump's strongest support was in the northwest of the state, including Mohave County, which was the only county to give him over 70% of the vote. Clinton did best in the southern-central region along the US-Mexico border. Santa Cruz and Pima counties (home to Tucson) were among her strongest and among the places in the state where she outperformed Barack Obama in 2012.

Electors
Arizona had 11 electors in 2016. All of them voted for Donald Trump for president and Mike Pence for vice president.

The electors were
 * Bruce Ash
 * Walter Begay
 * Sharon Giese
 * Robert Graham
 * Alberto Gutier
 * Jerry Hayden
 * Carole Joyce
 * Jane Pierpoint Lynch
 * J. Foster Morgan
 * James O'Connor
 * Edward Robson