The Detroit News broke with 143 years of support for the Republican Party this week to endorse Gary Johnson, the Libertarian candidate, arguing that Donald Trump is “unprincipled, unstable and quite possibly dangerous. He can not be president.”

The Arizona Republic went further. It has supported Republicans since 1890 but this year backs Hillary Clinton, writing that her flaws “pale in comparison” to Trump’s, whose “inability to control himself or be controlled by others represents a real threat to our national security.”

The Cincinnati Enquirer, Dallas Morning News and Houston Chronicle have also broken with longstanding traditions to support the Democrat this year. The latter calls Trump “a danger to the republic.”

The conservative New Hampshire Union Leader and Richmond Times-Dispatch have thrown their support behind Johnson.

The prospect of a Trump Administration even convinced USA Today, which has never endorsed a presidential candidate, to implore its readers to “resist the siren song of a dangerous demagogue. By all means vote,” the paper writes — “just not for Donald Trump.”

Who trusts newspapers anyway?

No candidate has ever faced such uniform hostility from the nation’s editorial boards.

Will it have an impact on the election?

NBC News’ political team wonders:

Maybe more importantly is the public’s lack of confidence in our elite institutions. In our April 2014 NBC/WSJ poll, just 19 percent of Americans said they had confidence in the news media; only 16 percent said they had confidence in the federal government; just 13 percent had confidence in large corporations; and only 13 percent had confidence in the financial industry.

If anything, they warn, elite collusion against Trump might play into his populist message — just like elite consensus in the United Kingdom about the foolhardiness of leaving the European Union only made some voters more determined to opt for “Brexit”.