NEW YORK • Fifty of America's most senior Republican national security officials, many of them former top aides or members of former president George W. Bush's Cabinet, have signed a letter declaring that Mr Donald Trump "lacks the character, values and experience" to be president and "would put at risk our country's national security and well-being".
The officials warned on Monday that Mr Trump "would be the most reckless president in American history".
The letter says he would weaken the United States' moral authority, and questions his knowledge of and belief in the Constitution. It says he has "demonstrated repeatedly that he has little understanding" of the nation's "vital national interests, its complex diplomatic challenges, its indispensable alliances and the democratic values" on which US policy should be based. And it laments that "Mr Trump has shown no interest in educating himself".
"None of us will vote for Donald Trump," it says, noting also that many Americans "have doubts about Hillary Clinton, as do many of us".
Late on Monday, Mr Trump struck back. The signatories of the letter, he said in a statement, were "the ones the American people should look to for answers on why the world is a mess, and we thank them for coming forward so everyone in the country knows who deserves the blame for making the world such a dangerous place".
He called them "nothing more than the failed Washington elite looking to hold onto their power".
Mr Trump correctly identified many of the signatories as the architects of the invasion of Iraq and its aftermath. But he also blamed them for allowing Americans "to die in Benghazi" and for permitting "the rise of ISIS" - referring to the 2012 attacks on the US mission in Libya and the spread of the Islamic State in Iraq and Syria, both during the Obama administration.
Among the most prominent signatories are Mr Michael Hayden, a former director of both the CIA and the National Security Agency; Mr John Negroponte, who served as the first director of national intelligence and then deputy secretary of state; and Mr Robert Zoellick, former deputy secretary of state, US trade representative and, until 2012, president of the World Bank.
A number have said they changed their minds once they heard Mr Trump invite Russia to hack into Mrs Clinton's e-mail server and say that he would check to see how much Nato members contributed to the alliance before sending forces to help stave off a Russian attack.
Their disavowal of the Republican presidential candidate was followed by another setback, when influential Senator Susan Collins said yesterday that Mr Trump was "unworthy" of America's highest elective office, and will not receive her support.
"This is not a decision I make lightly... Donald Trump does not reflect historical Republican values nor the inclusive approach to governing that is critical to healing the divisions in our country," Ms Collins wrote in the Washington Post.
And Mr Evan McMullin, a former CIA official, announced on Monday that he would run for president as an independent.
Mr McMullin, who until recently worked on policy development with the House Republican Conference, has missed ballot deadlines in more than two dozen states but, as a Mormon, could take votes from Mr Trump in heavily Mormon Utah.
NEW YORK TIMES