The July 26-28 poll suggested that the country largely disagrees with President Donald Trump’s announcement this week that he will ban transgender personnel from the armed forces.
Still, the announcement pleased elements of Mr. Trump’s base who have been dismayed to see the president break so bitterly in recent days with Attorney General Jeff Sessions, a hard-line conservative.
Civil rights and transgender advocacy groups denounced the policy, with some vowing to challenge it in court. Pentagon officials expressed dismay that the president’s tweets could open them to lawsuits.
The ban would reverse the gradual transformation of the military under President Barack Obama, whose administration announced last year that transgender people could serve openly in the military. Mr. Obama’s defense secretary, Ashton B. Carter, also opened all combat roles to women and appointed the first openly gay Army secretary.
When asked to weigh in on the debate, 58 percent of adults agreed with the statement, “Transgender people should be allowed to serve in the military.” Twenty-seven percent said they should not while the rest answered “don’t know.”
Democrats mostly supported military service by transgender Americans while Republicans were more evenly split.
Among Republicans, 32 percent said transgender Americans should be allowed to serve, while 49 percent said they should not. Another 19 percent of Republicans said they don’t know.
The public was also divided over the impact of banning transgender service members. Some 32 percent said it would “hurt morale” in the military while 17 percent said it would “improve morale.” Another 33 percent felt it would “have no impact” and the rest said they don’t know.
When asked about the impact on military capabilities, 14 percent said prohibiting transgender service members made the military “more capable” while 43 percent said “no impact,” 22 percent said “less capable” and the rest said they don’t know.
This is another example of the Trumpster turning on yet another group. During the campaine Trump would say anything to anyone who would listen. Lie and brag about his abilities all in an attempt to get ellected. The snake oil salesman billed himself during the campaign as an ally of gay, lesbian, bisexual and transgender people.
The president, Ms. Sanders said, had concluded that allowing transgender people to serve openly “erodes military readiness and unit cohesion, and made the decision based on that.”
Mr. Mattis, who was on vacation, was silent on the new policy. People close to the defense secretary said he was appalled that Mr. Trump chose to unveil his decision in tweets, in part because of the message they sent to transgender active-duty service members, including those deployed overseas, that they were suddenly no longer welcome.
The policy would affect only a small portion of the approximately 1.3 million active-duty members of the military. Some 2,000 to 11,000 active-duty troops are transgender, according to a 2016 RAND Corporation study commissioned by the Pentagon, though estimates of the number of transgender service members have varied widely, and are sometimes as high as 15,000.
The study found that allowing transgender people to serve openly in the military would “have minimal impact on readiness and health care costs” for the Pentagon. It estimated that health care costs would rise $2.4 million to $8.4 million a year, representing an infinitesimal 0.04 to 0.13 percent increase in spending. Citing research into other countries that allow transgender people to serve, the study projected “little or no impact on unit cohesion, operational effectiveness or readiness” in the United States.
Lt. Commander Blake Dremann, a Navy supply corps officer who is transgender, said he found out his job was in danger when he turned on CNN on Wednesday morning. Commander Dremann came out as transgender to his commanders in 2015, and said they had been supportive of him.
He refused to criticize Mr. Trump — “we don’t criticize our commander in chief,” he said — but said the policy shift “is singling out a specific population in the military, who had been assured we were doing everything appropriate to continue our honorable service.”
He added: “And I will continue to do so, until the military tells me to hang up my boots.”
The announcement came amid the debate on Capitol Hill over the Obama-era practice of requiring the Pentagon to pay for medical treatment related to gender transition. Representative Vicky Hartzler, Republican of Missouri, has proposed an amendment to the spending bill that would bar the Pentagon from spending money on transition surgery or related hormone therapy, and other Republicans have pressed for similar provisions.
Mr. Mattis had worked behind the scenes to keep such language out of legislation, quietly lobbying Republican lawmakers not to attach the prohibitions, according to congressional and defense officials.
The president’s announcement, made in posts on his Twitter account, surprised many senior military officers and appeared to pre-empt an ongoing Pentagon review into its inclusion of transgender service members.
The United States’ top military officer, Marine Corps. General Joseph Dunford, said the military will not alter its current policies until it receives additional guidance from Trump’s secretary of defense.
Roger Kaikko, 61, a Trump voter near Cleveland, Ohio, who took the poll, said he disagrees with the president.
“Even the president shouldn’t be able to take rights away from some people just because he may not like them,” Kaikko said. “They’re people too. Unless they’re causing problems, they should serve just like anybody else.”