The signatories of a letter endorsing the Democratic vice president included former members of Congress, defense secretaries, C.I.A. directors and other national security officials.
More than 100 former national security officials from Republican administrations and former Republican members of Congress endorsed Vice President Kamala Harris on Wednesday after concluding that their party’s nominee, Donald J. Trump, is “unfit to serve again as president.”
In a letter to the public, the Republicans, including both vocal longtime Trump opponents and others who had not endorsed Joseph R. Biden Jr. in 2020, argued that while they might “disagree with Kamala Harris” on many issues, Mr. Trump had demonstrated “dangerous qualities.” Those include, they said, “unusual affinity” for dictators like President Vladimir V. Putin of Russia and “contempt for the norms of decent, ethical and lawful behavior.”
“As president,” the letter said, “he promoted daily chaos in government, praised our enemies and undermined our allies, politicized the military and disparaged our veterans, prioritized his personal interest above American interests and betrayed our values, democracy and this country’s founding documents.”
The letter condemned Mr. Trump’s incitement of the mob attack on the Capitol on Jan. 6, 2021, aimed at allowing him to hold onto power after losing an election, saying that “he has violated his oath of office and brought danger to our country.” It quoted Mr. Trump’s own former vice president, Mike Pence, who has said that “anyone who puts himself over the Constitution should never be president of the United States.”
The letter came not long after former Vice President Dick Cheney and his daughter, former Representative Liz Cheney of Wyoming, both said they would vote for Ms. Harris. Democrats featured a number of anti-Trump Republicans at their nominating convention last month, including former Representative Adam Kinzinger of Illinois. Mr. Pence has said he will not endorse Mr. Trump but has not endorsed Ms. Harris.
The 111 signatories included former officials who served under Ronald Reagan, George H.W. Bush or George W. Bush. Many of them had previously broken with Mr. Trump, including two former defense secretaries, Chuck Hagel and William S. Cohen; Robert B. Zoellick, a former president of the World Bank; the former C.I.A. directors Michael V. Hayden and William H. Webster; a former director of national intelligence, John D. Negroponte; and former Gov. William F. Weld of Massachusetts. Miles Taylor and Olivia Troye, two Trump administration officials who became vocal critics, also signed.
But a number of Republicans who did not sign a similar letter on behalf of Mr. Biden in 2020 signed the one for Ms. Harris this time, including several former House members, like Charles W. Boustany Jr. of Louisiana, Barbara Comstock of Virginia, Dan Miller of Florida and Bill Paxon of New York.
In their letter, the Republicans acknowledged concerns about “some of the positions advocated by the left wing of the Democratic Party,” and some of them have been quite critical of the Biden-Harris administration. Just last year, Mr. Zoellick wrote a newspaper essay eviscerating Democratic economic policies. But the letter said that “any potential concerns” about Ms. Harris “pale in comparison to” those over Mr. Trump.
