The final time Republicans in South Dakota made a critical push to bar transgender ladies from faculty sports activities, in 2019, their invoice was identified solely by its nondescript numerical title, Senate Bill 49. Its two principal sponsors had been males. And it died with out ever getting out of committee, simply 10 days after it was launched.

However when Republicans determined to strive once more in January, they had been much more strategic of their strategy. The sponsors this time had been two girls who modeled their bill after a template supplied by a conservative authorized group. They gave the invoice a reputation that urged noble intent: the “act to advertise continued equity in girls’s sports activities.” Supporters from Minnesota and Idaho traveled to the Capitol in Pierre to testify {that a} new legislation was urgently wanted to maintain anybody with male organic traits out of feminine competitions, despite the fact that they acknowledged solely a handful of examples of that occuring in South Dakota.

“These efforts seem like much more slick, and much more organized,” stated Elizabeth A. Skarin of the American Civil Liberties Union of South Dakota, which opposes the invoice. “Anytime they offer a invoice a reputation in South Dakota,” she added, “you understand one thing’s up.”

Then issues took an sudden flip. Gov. Kristi Noem, who’s seen as a attainable contender for the Republican presidential nomination in 2024, demanded modifications to the invoice earlier than she would signal it. The response was swift and harsh: Social conservative activists and Republican lawmakers accused Ms. Noem of being cowed by stress from enterprise and athletics organizations, which have been profitable at stopping legal guidelines in different states that single out transgender folks for exclusion and feed ugly stereotypes.

South Dakota is only one of a rising variety of states the place Republicans are diving right into a tradition battle conflict that appears to have come out of nowhere. It has been led to by a coordinated and poll-tested marketing campaign by social conservative organizations just like the American Ideas Venture and Involved Ladies for America. The teams are decided to maneuver ahead with what could also be considered one of their final footholds within the combat towards increasing L.G.B.T.Q. rights.

Three different states have handed payments this month that resemble South Dakota’s. In Mississippi and Arkansas, they’re set to change into legislation this summer time. And related payments have been launched by Republicans in two dozen different states, together with North Carolina, the place an unpopular “bathroom bill” enacted in 2016 prompted costly boycotts and led conservatives nationwide to drag again on efforts to limit rights for transgender folks.

“You make change in our society by making legal guidelines, and by chance we have now some nice states which have stepped up,” stated Beth Stelzer, the founding father of a brand new group, Save Ladies’s Sports activities, that she stated opposes “demolishing girls’s sports activities for the sake of emotions.” Ms. Stelzer, an beginner energy lifter who was in North Carolina this week for the invoice introduction, has additionally testified in help of recent legal guidelines in South Dakota, Montana and Arkansas.

Former President Donald J. Trump, who steered away from the problem within the 2020 marketing campaign, shocked activists when he lent momentum to it at a conservative convention final month, saying that “women’s sports as we know it will die’’ if transgender athletes had been allowed to compete.

However the concept that there’s a sudden inflow of transgender rivals who’re dominating girls’s and ladies’ sports activities doesn’t replicate actuality — in highschool, school or professionally. Sports activities associations just like the N.C.A.A., which has promoted the inclusion of transgender athletes, have insurance policies in place to handle considerations about bodily variations in female and male biology. The N.C.A.A., for instance, requires athletes who’re transitioning to feminine to be on testosterone suppression remedy for a yr earlier than they’ll compete on a girls’s workforce.

Ms. Stelzer, who competes in a weight lifting league that doesn’t permit transgender girls to take part, says the purpose is to get forward of what she and different activists consider will change into an even bigger concern. “We’re nipping it within the bud,” she stated.

In highschool sports activities, the place conservative activists have centered a lot of their consideration, insurance policies differ broadly. Some states pose no obstacles to transgender athletes; some have insurance policies just like these of the N.C.A.A. that set pointers round hormone remedy; others have outright bans or demand that college students confirm their intercourse if questioned.

Not often has a difficulty that so few folks encounter — and one which public opinion analysts have solely lately begun to study in depth — change into a political and cultural flash level so rapidly. The lack of information creates an surroundings during which the actual impression of transgender participation in sports activities may be overshadowed by hyperbole.

However the debate additionally raises questions — that ethicists, lawmakers and the courts are solely starting to handle — about whether or not the decades-long effort to offer girls and ladies equal alternatives in sports activities is suitable with efforts to offer transgender folks equal alternatives in life. A lawsuit in federal courtroom in Connecticut introduced by three highschool runners who misplaced in competitors towards transgender ladies will probably be among the many first to check how nondiscrimination legal guidelines apply.

A mixture of components has helped social conservatives breathe new life into the problem: activists who agreed to surrender on unpopular payments regulating public loos; an consciousness that ladies, not males, might be extra persuasive and sympathetic advocates; a brand new Democratic administration that rapidly moved to broaden and restore rights for transgender people who the Trump administration had eradicated; and a political and media tradition on the best that usually reduces the nuanced concern of gender identification to a punchline about political correctness.

Activists who’ve been combating the anti-transgender efforts in legislatures and thru the courts say the give attention to faculty athletics is making a false and misplaced notion of victimization.

“There’s a way that there’s a sufferer of transness,” stated Chase Strangio, a lawyer with the A.C.L.U., which was profitable in quickly blocking the implementation of a transgender athlete ban in Idaho final yr.

In reality, research have proven that the majority of transgender students report feeling unsafe at college due to bullying and harassment.

“What we have now is a speculative worry of one thing that hasn’t materialized,” Mr. Strangio, who’s a transgender man, added. “They’re appearing like LeBron James goes to placed on a wig and play basketball with fourth graders. And never one LeBron James, 100. In actuality, you’re speaking about little children who simply need to play rec sports activities. They only need to get by life.”

However the remoted cases which have been filmed or generated headlines — feminine weight lifting data being damaged by a brand new transgender competitor, for instance — make for viral content material, bolstered by media personalities with large followings like Ben Shapiro, Tucker Carlson and Joe Rogan.

The difficulty is way more broadly lined in conservative media — and sometimes offered with a heavy dose of sarcasm. In accordance with a evaluation of social media content material performed for The New York Occasions by Media Issues, a left-leaning watchdog, seven of the ten hottest tales in regards to the proposed legal guidelines concentrating on transgender folks up to now this yr had been from the Every day Wire, a web site based by Mr. Shapiro. Two others had been from Fox Information. Mixed, the articles had been learn, shared and commented on six million instances, Media Issues stated.

The heightened media consciousness on the best is due partly to how social conservative activists have improved at packaging transgender-specific restrictions. Borrowing a web page from the anti-abortion motion, which was led by males for a lot of its early interval, they’ve begun that includes girls as public advocates.

In Arkansas, the place the governor signed the “Fairness in Women’s Sports Act” into legislation final week, the main proponents had been the lawyer common, Leslie Rutledge, who’s a candidate for governor, and the Arkansas Republican Ladies’s Caucus. The invoice will prohibit transgender participation on feminine groups from kindergarten by school.

In lots of cases, lawmakers have labored carefully with teams just like the Alliance Defending Freedom, a conservative authorized group that has argued a number of Supreme Courtroom circumstances on behalf of individuals claiming discrimination due to their conventional beliefs about marriage and gender roles. Offering messaging, polling and political help are teams just like the American Ideas Venture, Involved Ladies for America and the Heritage Basis.

Within the ongoing case in Idaho, opponents of the legislation argued that it was exclusionary, discriminatory and a violation of the Equal Safety Clause of the Structure. The Alliance Defending Freedom, which is representing two feminine school runners who stated that they had “deflating experiences” after dropping to a transgender lady, agreed that the case was about equality, however within the context of making “a stage enjoying area.”

“When the legislation ignores the professional variations that exist between women and men, it creates chaos,” stated Kristen Waggoner, the group’s common counsel. “It additionally creates huge unfairness for girls and ladies in athletics.”

Limiting the rights of transgender folks is a matter that has resonance with an more and more small share of the general inhabitants. A new study by the Public Faith Analysis Institute reported that solely 7 p.c of People are “fully towards” pro-L.G.B. T.Q. insurance policies. However it’s a vocal group intent on displaying that it will probably flex its energy within the Republican Occasion.

When Ms. Noem despatched the invoice again to the South Dakota Legislature on March 19, regardless of having said on Twitter that she was “excited to signal this invoice very quickly,” social conservative organizations went on the assault, taking purpose at her obvious presidential ambitions as a possible Achilles’ heel. “It’s no secret that Gov. Noem has nationwide aspirations, so it’s time she hears from a nationwide viewers,” the Household Coverage Alliance, an affiliate of Give attention to the Household, wrote in an e mail to supporters.

Ms. Noem appeared to concentrate on how damaging it might be to have conservatives suppose she was on the mistaken facet of the problem.

On Thursday, she and her advisers joined a unexpectedly organized convention name with members of the Conservative Motion Venture, which incorporates leaders of the most important right-wing teams within the nation. Ms. Noem expressed concern that if she signed the legislation, the N.C.A.A. would retaliate towards South Dakota, because it did with North Carolina, by refusing to carry tournaments there, in line with one particular person on the decision. She has stated she’s going to signal the invoice provided that the provisions that apply to varsity athletics are taken out.

The activists had been respectful however clear, this particular person stated, telling her this was not what they anticipated from the conservative firebrand that they had come to admire a lot.