The final time Republicans in South Dakota made a severe 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 foremost sponsors have 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 have been much more strategic of their strategy. The sponsors this time have been two girls who modeled their bill after a template offered by a conservative authorized group. They gave the invoice a reputation that recommended 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 regulation was urgently wanted to maintain anybody with male organic traits out of feminine competitions, although they acknowledged solely a handful of examples of that taking place in South Dakota.

“These efforts look 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 provide a invoice a reputation in South Dakota,” she added, “you already know one thing’s up.”

Then issues took an sudden flip. Gov. Kristi Noem, who’s seen as a doable 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 warfare conflict that appears to have come out of nowhere. It has been caused by a coordinated and poll-tested marketing campaign by social conservative organizations just like the American Rules Challenge and Involved Girls for America. The teams are decided to maneuver ahead with what could also be certainly one of their final footholds within the battle in opposition to 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 turn into regulation this summer season. 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 fortunately now we have some nice states which have stepped up,” stated Beth Stelzer, the founding father of a brand new group, Save Girls’s Sports activities, that she stated opposes “demolishing girls’s sports activities for the sake of emotions.” Ms. Stelzer, an newbie energy lifter who was in North Carolina this week for the invoice introduction, has additionally testified in help of latest 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 have 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, faculty 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 crew.

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

In highschool sports activities, the place conservative activists have targeted a lot of their consideration, insurance policies range extensively. Some states pose no limitations to transgender athletes; some have insurance policies much 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 problem that so few folks encounter — and one which public opinion analysts have solely just lately begun to study in depth — turn into a political and cultural flash level so shortly. The ignorance creates an setting wherein the true affect of transgender participation in sports activities will 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 appropriate 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 in opposition to transgender ladies might be among the many first to check how nondiscrimination legal guidelines apply.

A mixture of elements has helped social conservatives breathe new life into the problem: activists who agreed to surrender on unpopular payments regulating public bogs; an consciousness that girls, not males, might be extra persuasive and sympathetic advocates; a brand new Democratic administration that shortly moved to broaden and restore rights for transgender those that the Trump administration had eradicated; and a political and media tradition on the correct that always reduces the nuanced subject of gender identification to a punchline about political correctness.

Activists who’ve been preventing the anti-transgender efforts in legislatures and thru the courts say the deal with 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 in school due to bullying and harassment.

“What now we have is a speculative concern 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 simply need to get via life.”

However the remoted cases which were 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 enormous followings like Ben Shapiro, Tucker Carlson and Joe Rogan.

The problem is way more extensively coated in conservative media — and infrequently introduced with a heavy dose of sarcasm. Based on a overview 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 to this point this yr have been from the Day by day Wire, a web site based by Mr. Shapiro. Two others have been from Fox Information. Mixed, the articles have been learn, shared and commented on six million occasions, Media Issues stated.

The heightened media consciousness on the correct is due partially 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 regulation final week, the main proponents have been the legal professional common, Leslie Rutledge, who’s a candidate for governor, and the Arkansas Republican Girls’s Caucus. The invoice will prohibit transgender participation on feminine groups from kindergarten via faculty.

In lots of cases, lawmakers have labored intently with teams just like the Alliance Defending Freedom, a conservative authorized group that has argued a number of Supreme Court docket 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 Rules Challenge, Involved Girls for America and the Heritage Basis.

Within the ongoing case in Idaho, opponents of the regulation 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 faculty runners who stated that they had “deflating experiences” after dropping to a transgender girl, agreed that the case was about equality, however within the context of making “a degree taking part in area.”

“When the regulation ignores the reputable variations that exist between women and men, it creates chaos,” stated Kristen Waggoner, the group’s common counsel. “It additionally creates huge unfairness for ladies 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 % of Individuals are “fully in opposition to” pro-L.G.B. T.Q. insurance policies. However it’s a vocal group intent on displaying that it will possibly flex its energy within the Republican Social gathering.

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 goal 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 Concentrate on the Household, wrote in an e-mail to supporters.

Ms. Noem appeared to pay attention to how damaging it might be to have conservatives assume she was on the mistaken aspect of the problem.

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

The activists have 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.