111 Former G.O.P. Officials Back Harris, Calling Trump ‘Unfit to Serve’

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