Eighteen years ago, when Democrats controlled state government in Iowa, Gov. Chet Culver signed civil rights protections for gay, lesbian and transgender people into law.
“We send a message that Iowa is a welcoming place that values each of its citizens, whether it’s in the neighborhood or in the workplace,” Mr. Culver said at the time. “We send a message that intolerance and discrimination have no place in our state.”
On Thursday, in an Iowa State Capitol now dominated by Republicans, lawmakers passed a bill that would remove those civil rights guarantees from transgender Iowans. Advocates for L.G.B.T.Q. rights said Iowa would become the first state to remove broad and explicit protections for transgender people if Gov. Kim Reynolds, a Republican, signed the measure.
The debate in Des Moines, where protesters and Democrats tried without success this week to persuade Republican lawmakers to reconsider, reflected how much the discourse over transgender issues has shifted in the country, and how much Iowa has changed.
The passage of the Iowa legislation comes as the Trump administration has tried to limit official recognition of transgender identity.
The administration has sought to end funding for hospitals that provide gender-transition treatments to minors, to bar transgender women and girls from competing in women’s sports, to bar openly transgender people from serving in the military, to house transgender women in federal prisons with men, and to no longer reflect the gender identities of transgender people on passports.
The bill in Iowa defines sex based on a person’s anatomy at birth and removes gender identity from a list of protected groups that employers, businesses and landlords may not discriminate against. The measure leaves in place discrimination protections for gay and lesbian people.
In testimony at the Capitol on Thursday, opponents of the legislation told lawmakers that they feared transgender people would face widespread discrimination and harassment if the civil rights protections were removed. Many supporters of the bill said they believed that sex was determined at birth and that they worried about transgender women using women’s restrooms. Several speakers on both sides of the issue cited their Christian faith.
“I’m outraged that biological males have a legal right in Iowa to force themselves into my wife’s, daughters’ and granddaughters’ private spaces,” Chuck Hurley of The FAMiLY Leader, a group based in Iowa that describes itself as a Christian ministry to government, told a legislative committee on Thursday.
Minutes later, the Rev. Debbie Griffin, who pastors a church in Des Moines, urged lawmakers to reject the bill, warning that it “would endanger people who are already vulnerable to bullying and discrimination.”
On the federal level, the Supreme Court ruled several years ago that the Civil Rights Act of 1964 protected gay and transgender people from workplace discrimination. Efforts by Democrats in Congress to expand the scope of those protections beyond the workplace have failed.
More than 20 states, most of them led by Democrats, have explicit employment discrimination protections for transgender people, according to information compiled by the Movement Advancement Project, a think tank that supports L.G.B.T.Q. rights.
A spokesman for Governor Reynolds did not immediately respond to questions before or after the votes on Thursday about whether she had a position on the legislation or planned to sign it. She has previously signed laws that banned gender-transition treatments for minors and that kept transgender girls and women from competing in women’s sports.
Those measures have been part of a broader push by Iowa Republicans into social issues that voters have so far rewarded at the ballot box. In recent years, Ms. Reynolds and legislative Republicans have passed laws to restrict abortion, ban school library books deemed sexually explicit and allow for state-level immigration enforcement.
Democrats have struggled to push back. Former President Barack Obama carried Iowa twice, but Republicans have seen their support surge since President Trump became the party’s leader. Mr. Trump carried Iowa last year by about 13 percentage points, winning 94 of its 99 counties, and Republicans retained large state legislative majorities. A surprise win by a Democrat in a special legislative election last month was a rare bright spot for that party.
In floor debates on Thursday, some Republicans said they were concerned that keeping civil rights protections for gender identity would leave other state laws — like those restricting gender-transition treatments for minors and sports participation by transgender women — vulnerable to legal challenges.
“All of these common-sense policies are at risk so long as gender identity remains in the Iowa civil rights code,” State Representative Steven Holt, a Republican supporter of the bill, said on the House floor.
Democrats called the bill an attack on civil rights, and urged Republicans to vote it down in a series of speeches that were cheered loudly by spectators in the gallery.
State Representative Aime Wichtendahl, a Democrat who is transgender, said she worried about discrimination against transgender people if the measure passed, and told her colleagues that “I transitioned to save my life.”
“The purpose of this bill, the purpose of every anti-trans bill,” Ms. Wichtendahl said, “is to further erase us from public life and to stigmatize our existence.”
Amy Harmon contributed reporting.
