Nearly all have failed or stalled. If anything, the tide has even turned among Republicans. The former governor of South Dakota, Dennis Daugaard, vetoed a 2016 bill that would have created a law stopping transgender people from using the bathroom that corresponds to their gender identity. And when lawmakers tried again the next year, he threatened another veto. In Texas last year, Gov. Greg Abbott backed away from supporting a “bathroom bill,” as the proposals are known, even though he had pushed for one the previous year.

The biggest battle to date was in North Carolina, which passed and then repealed a bill that required people to use the bathroom in public facilities that matched the gender on their birth certificate. The backlash against the measure, which included a decision by the N.C.A.A. not to host basketball games in the state, was a factor in the 2016 defeat of former Gov. Pat McCrory, the Republican who had signed the law earlier that year.

According to a poll commissioned by the Human Rights Campaign after the election, 57 percent of voters said the bill was the top reason they had voted against Mr. McCrory. Public polling conducted after the measure passed found that 55 percent of voters wanted it repealed.

And the country as a whole has been growing more tolerant on trans issues. A survey released in June by the Public Religion Research Institute found that more than six in 10 Americans said they were more supportive of transgender rights than they had been five years ago. Though the report also added a caveat: “Conservative Republicans (40%) stand out as the only ideological group with less than half reporting increased support for transgender rights.”

Lately, a series of high-profile incidents involving transgender children has emboldened social conservatives, including a bitter custody dispute between two parents in Texas who disagree over how to treat their 7-year-old child’s gender identity issues. The father has become a cause célèbre in conservative media and drawn support from Republican politicians like Senator Ted Cruz of Texas because he has said he does not believe the child identifies as a girl, and does not want the child to receive medical treatment to transition, if that becomes necessary in the future.

Admittedly, social conservatives have found themselves struggling with how to articulate their case.