Yet it would be a sharp rebuke for former Trump administration officials and well-known Republicans to buck their own standard-bearer. Individually, they may not sway many votes — particularly at a time of deep polarization. But their collective opposition, or even resounding silence, could offer something of a permission structure for Trump-skeptical Republicans to put party loyalty aside.
John Kelly, Mr. Trump’s former chief of staff and a retired Marine general, would not say whom he would vote for, though he did allow that he wished “we had some additional choices.”
Dan Coats, the former Republican senator who was Mr. Trump’s director of national intelligence, “has been concerned about the negative effect on the intelligence community by the turmoil of turnover at D.N.I.,” said Kevin Kellems, a longtime adviser to Mr. Coats, adding that the former spy chief is “encouraged by the confirmation of a new D.N.I. and career intelligence deputy.”
As for whom Mr. Coats will vote for, “ultimately he remains a loyal Republican but he believes the American people will decide on Nov. 3,” said Mr. Kellems.
Joseph Maguire, a retired three-star admiral who served as Mr. Trump’s acting intelligence chief, invoked the comments of Mr. Mattis and two former chairmen of the Joint Chiefs of Staff who also criticized the president this week.
“Jim Mattis, Mike Mullen and Marty Dempsey are all good friends, and I respect them tremendously,” Admiral Maguire said in an interview. “I am in alignment with their views.”
Asked who Mr. Boehner and Mr. Ryan will vote for in November, representatives to both former House speakers declined to say.
Former Secretary of State Condoleezza Rice, asked if she would support Mr. Trump for re-election, said on CBS’s “Face the Nation” that she didn’t want to discuss politics right now, adding that her focus was on addressing divisions in the country. She did not support Mr. Trump in 2016.
A number of current G.O.P. lawmakers and governors are also wrestling with what to do — and what to say — as they balance conscience, ideology and the risk to themselves and their constituents that comes from confronting Mr. Trump.