A series of American newspapers break the rules and support Hillary Clinton for president.

Many major newspapers in the US broke with tradition and decided to support Hillary Clinton in the race for the White House, causing them to face death threats and boycotts from readers.

Republican presidential candidate Donald Trump (left) and Democratic candidate Hillary Clinton. Photo: Reuters.

The Phoenix-based Arizona Republic, Arizona’s largest newspaper, published an editorial on September 27 in support of the Democratic Party, arguing that Republican Donald Trump was unqualified to be president. This was the first time the Arizona Republic had endorsed a political party since its founding in 1890.

The newspaper's editorial board said Hillary Clinton also has flaws but she is currently the "better choice".

The Arizona Republic immediately received a series of angry emails from readers asking them to cancel their subscriptions, AFP quoted Phil Boas, editorial page editor, as saying on September 29. The newspaper also received several death threats. The editorial board had expected this and does not regret its decision to support Clinton.

USA Today also broke with tradition yesterday for the first time in its 34 years of operation when its editorial board leaned toward one candidate in the race for the White House, although it did not directly state who it supported.

USA Today published an article criticizing Trump, calling on readers to oppose a candidate described as "dangerous" and "unfit to be president." The newspaper also called him "erratic, unprepared," with a "stormy" business past and a "serial liar."

In addition to the Arizona Republic and USA Today, many other newspapers in the US also leaned towards Mrs. Clinton. The Cincinnati Enquirer, an Ohio newspaper that has supported the Republican Party for nearly a century, announced last week that it was supporting Clinton because "Trump is clearly a danger to the country."

The Dallas Morning News, based in the Republican-majority state of Texas, also endorsed the Democratic candidate for the first time in 75 years, calling her "the only serious candidate." The two newspapers also faced backlash, with readers boycotting them.

Boas, a Republican, said the Arizona Republic made the decision to support Democrats easily based on Trump's proposals and behavior.

"We would be shocked and appalled if our children and grandchildren behaved like him," he said, adding that many Republicans understand that "but are in denial." "I think a lot of people know that this candidate violates their values. They compromise by not liking Hillary Clinton... it's time for Republicans and conservatives to wake up."

According to VNE