The biggest political crisis of Indiana Gov. Mike Pence's career is over a type of law that's been around for more than 20 years.

Indiana's new Religious Freedom Restoration Act (RFRA), which Pence signed into law on March 26, says government can't intrude on a person's religious rights unless it has a compelling government interest and is acting in the least intrusive way possible.

Although RFRAs have been passed with little fanfare in 19 other states and at the federal level since the early 1990s, Indiana's law — which critics say could legally protect employers, landlords, and business owners who discriminate against LGBT people on religious grounds — has made Pence the central figure in a new civil rights battle.

In response to the national firestorm, Pence on April 2 approved a clarification to the RFRA that will bar businesses and individuals from using the law to refuse employment, housing, or service to people based on their sexual orientation or gender identity. The clarification will exempt churches and other nonprofit religious organizations.

The change was a result of a week of nationwide pressure from public figures and businesses. Renowned Star Trek actor George Takei has called for a boycott of the state. Angie's List, an online consumer ratings service, withdrew a $40 million expansion of its headquarters in Indianapolis. Apple CEO Tim Cook penned a Washington Post column describing the law and others like it as "very dangerous." And the state's biggest newspaper, the Indianapolis Star, expressed its opinion on the front page of its Tuesday issue:

While Pence insisted the original law had nothing to do with LGBT rights, the law's supporters said it would allow, for example, religious business owners to refuse service to gay and lesbian couples because of their sexual orientation.

Legal experts doubted Indiana's original religious freedom law could have been used to justify discrimination, as no other laws like it have been used that way since the federal government passed the first of its kind almost 22 years ago. But even though these laws might not have changed much over the years, public opinion certainly has. And legislation that was not controversial — or related to LGBT discrimination at all — in the '90s was enough to set off a political firestorm in 2015.

Religious freedom laws have existed for more than two decades

RFRAs have been around since President Bill Clinton approved a federal version of the law in 1993.

Traditionally, the laws have been used to protect religious minorities. The Indianapolis Star's Stephanie Wang reported a case in Minnesota in which a law would have required Amish buggies to use bright fluorescent signs to be more easily detectable on roads. A court agreed the government has a compelling interest to uphold public safety on the roads, but that it could do so in a manner that doesn't burden Amish religious adherence to a simple lifestyle. In the end, the fluorescent signs were replaced with silver reflective tape and kerosene lanterns.

"These are, frankly, plain, vanilla religious protections," Robin Wilson, a law professor at the University of Illinois, said.

"These are, frankly, plain, vanilla religious protections"

The laws first came about after a 1990 Supreme Court decision in which the court ruled someone could be fired for using peyote, a hallucinogenic drug, during a religious Native American ceremony, Wilson said. Although the court ruled against the religious argument in that case, it suggested that governments could establish explicit protections that would exempt people from certain laws if they have a genuine religious objection. The ruling eventually convinced the federal government to pass its RFRA in 1993.

Following the enactment of the federal RFRA, the US Supreme Court ruled in 1997 that the federal law only applies religious protections in the context of other federal laws. The decision compelled states to pass their own measures, so the legal protections for religious rights apply to the local and state level as well.

Indiana's law, which goes into effect on July 1, goes further in one significant way than traditional RFRA laws. As South Texas College of Law professor Josh Blackman explained in a blog post, it's unclear — and varies from court to court — whether the federal RFRA can be cited as a defense in lawsuits in which the government isn't one of the parties involved. But Indiana's law explicitly states that a person can cite the state's RFRA in private lawsuits in which the government isn't a party. That means someone could cite Indiana's RFRA as a defense in a private lawsuit, instead of just legal disputes with governments.

The fight over Indiana's RFRA shows a changing political landscape

It's true the first RFRA was passed in 1993 to support religious minorities. But in recent years — as same-sex marriage bans have been struck down by courts across the country — social conservatives have used the measures to appeal to a base that's still opposed to LGBT rights.

In a March 29 interview with ABC News's George Stephanopoulos, Pence seemed genuinely befuddled that his state was getting so much attention for approving a law that exists at the federal level and in 19 other states. He took particular issue with the suggestion that Indiana's RFRA could allow employers, landlords, and business owners to discriminate on religious grounds.

"This is where this debate has gone with misinformation," Pence said. "There's been shameless rhetoric about my state and about this law and about its intention."

"There's been shameless rhetoric about my state and about this law and about its intention"

But this rhetoric has been perpetuated in part by RFRA supporters. In Indiana, Advance America, a local conservative organization, said on its website that the state's RFRA would help "Christian bakers, florists and photographers" so they're not "punished for refusing to participate in a homosexual marriage!" In Georgia, after a gay-friendly Republican lawmaker included protections for LGBT people in an RFRA bill, legislators tabled it at the last minute — suggesting that the bill really did have something to do with LGBT rights.

The biggest fear for LGBT advocates was that the law would allow open discrimination of gay, lesbian, bisexual, and transgender Hoosiers — not just in bakeries and hotels that will deny service to LGBT people, but among employers who will refuse to hire them or landlords who will reject housing applications. Some even raised fears about "no gays allowed" signs at stores, drawing a troubling comparison to the days of government-sanctioned segregation in the South.

Pence didn't do much to alleviate this perception. When Stephanopoulos asked the governor whether the law would allow discrimination against LGBT people, he refused to give a yes or no answer. He also told the Indianapolis Star's Tim Swarens that it's not on his agenda to add explicit legal protections for gays and lesbians. The latter comment drew ire from LGBT advocates, including Ian Thompson at the American Civil Liberties Union, who questioned Pence's motives on Twitter:

If #SB101 wasn't intended to provide a license to discriminate why not make explicit that it can't be used for that purpose, @GovPenceIN? — Ian Thompson (@iantDC) March 29, 2015

The big difference between the RFRAs passed in other states and Indiana's law is the political landscape. Other RFRAs were passed when LGBT rights weren't a mainstream issue in the US. But after the rapid spread of same-sex marriage rights in the US over the past couple of years, LGBT issues are now a major civil rights battleground — making any law that potentially touches on these issues very contentious.

"Where things went south in Indiana," Wilson of the University of Illinois said, "is the fact that we're at a very important moment in time, socially, where we have had a dramatic shift in marriage rights for gay folks."

Blackman of South Texas College of Law said RFRA supporters' claims that religious freedom laws allow LGBT discrimination are "pandering" to get the law approved; he doesn't believe the original RFRA would have allowed this type of discrimination, even without the clarification passed on April 2.

But the comments showed lawmakers were pushing the law in part to draw support from anti-LGBT constituencies, who feel bitter and defeated as same-sex marriages become law in more and more states. And the claims from RFRA supporters in turn fostered a backlash from LGBT advocates who genuinely feared that religious freedom laws really could be used as a license to discriminate. By trying to drive support for Indiana's RFRA with anti-LGBT claims, supporters of Pence helped foster the same backlash they saw in Indiana.

Legal experts doubt religious freedom laws will protect discrimination

Despite the claims of supporters and critics of RFRAs, legal experts are skeptical that the laws can be successfully used to defend legally prohibited forms of discrimination in court.

The basic argument, presented by both proponents and opponents, is that the laws give more latitude to employers, landlords, and business owners to deny employment, housing, and service to LGBT people, even in places where local or state laws protect people from discrimination based on sexual orientation and gender identity.

For example, an Indianapolis baker could try to cite Indiana's RFRA to refuse service to gay couples because he's religiously opposed to same-sex marriages, even though the city legally prohibits discrimination based on sexual orientation.

The clarification eliminates any concern: it will prevent individuals and businesses from using the law to refuse employment, housing, or service to people based on their sexual orientation or gender identity

"this is not going to give you a blank check for bigotry"

Wilson of the University of Illinois expected some people would try an RFRA-based defense for discrimination under the original, but she believed they'd ultimately lose. She said courts would have ruled that local and state governments have a compelling interest to protect LGBT rights, even if it would conflict with some people's religious beliefs. "In a contest of gay rights and religious rights under RFRAs, religious rights are going to lose," Wilson said.

There are decades of legal precedent to support Wilson's claim. RFRAs have never been successfully used in their 22-year existence to allow discrimination, including in cases in New Mexico and Washington state, which has an RFRA standard through court rulings, that involved businesses refusing service to same-sex couples, according to Douglas Laycock, a law professor at the University of Virginia. "There are hardly any cases about discrimination," he wrote in an email to the Weekly Standard, "and nobody has ever won a religious exemption from a discrimination law under a RFRA standard."

It's possible a court could eventually rule differently and try to expand the scope of RFRAs, but legal scholars are skeptical of the possibility. "If you read the law, and look at how the cases have developed over the past 20 years, this is not going to give you a blank check for bigotry," Blackman said. "It's going to be a very rare case where religion can be used as a defense for discrimination claims."

States could get ahead of any of these issues by including exemptions for civil rights laws in their RFRAs. Texas's RFRA includes a carve-out for civil rights protections to prevent people from citing their religious beliefs as a license to discriminate. Indiana's original law included no such exemption, but the clarification passed on April 2 does.

The Supreme Court's Hobby Lobby decision added to the controversy

If not for a Supreme Court decision over Obamacare, it's possible Indiana's RFRA wouldn't have fallen under so much scrutiny.

In 2014, the US Supreme Court cited the federal RFRA to exempt some employers from Obamacare's birth control mandate, which requires all employer-provided health plans to cover FDA-approved contraceptives without any cost-sharing for the patient. The ruling exempted closely held corporations — notably, Hobby Lobby — whose owners have religious objections to some of the forms of birth control covered by the mandate.

THE MAJORITY OPINION SUGGESTED RELIGIOUS BELIEFS CAN'T BE USED TO JUSTIFY WORKPLACE DISCRIMINATION

A similar ruling, LGBT advocates contend, could be applied to federal, state, or local nondiscrimination protections.

Wilson of the University of Illinois doubts courts will rule in favor of anti-LGBT discrimination on religious grounds, but she acknowledged the Supreme Court's Hobby Lobby decision "did kick this up to a whole new level of urgency." She said that by protecting a major for-profit company (Hobby Lobby) that followed a majority religion (Christianity), the court interpreted the law in a way that goes far beyond protecting religious minorities like the Amish and Native Americans.

But the majority opinion in the case, written by Justice Samuel Alito, suggested religious beliefs can't be used to justify workplace discrimination, although it only mentioned race as an example. "The principal dissent raises the possibility that discrimination in hiring, for example on the basis of race, might be cloaked as religious practice to escape legal sanction," Alito wrote. "Our decision today provides no such shield. The Government has a compelling interest in providing an equal opportunity to participate in the workforce without regard to race, and prohibitions on racial discrimination are precisely tailored to achieve that critical goal."

Still, the Hobby Lobby decision helped create a perception that RFRAs could be used to carve out major exemptions in big laws, regardless of their actual effects.

Businesses have threatened states over passing RFRAs

Outraged over Indiana Freedom to Discriminate law, signed today. LGBTs aren't 2nd class citizens. #BoycottIndiana #Pence — George Takei (@GeorgeTakei) March 26, 2015

Much of the backlash to Indiana's law was amplified by social media reactions from celebrities and businesses, who said Indiana's original law — before the clarification — signaled that LGBT people are no longer welcome in the state.

For public figures like Takei, part of their opposition to the original Indiana law and other religious freedom laws was personal. The actor wrote on Facebook that Gov. Pence's approval of the law "made it clear that LGBT couples, like Brad and me, are now unwelcome in his state."

But for businesses, there's a more practical reason for opposing the laws: if the laws create a perception that LGBT individuals aren't welcome in Indiana, that could make it more difficult to attract talent from around the world. "We're unwilling to engage in an economic development agreement that's contingent on us hiring people in when the state is sending a message out to potential employees that is not always palatable," Angie's List CEO Bill Oesterle said at a press conference.

"[Gov. Pence] has made it clear that LGBT couples, like Brad and me, are now unwelcome in his state"

Other businesses, including Apple, Salesforce, and Yelp, have condemned the laws, with some threatening to stop doing business in states that pass RFRAs without civil rights exemptions.

The backlash to Indiana's law isn't the first time businesses have threatened action in response to a religious freedom law. When Arizona considered a similar measure, the NFL suggested it could move the Super Bowl in response to the bill. The pressure was one of the reasons Arizona Gov. Jan Brewer (R) ultimately vetoed the bill.

It's too late for Pence to veto the Indiana RFRA, but legislators are moving to clarify the law to make it clear that it won't allow discrimination against anyone, including LGBT people.

The real LGBT rights battle is over nondiscrimination laws

Although the fight over Indiana's RFRA was the loudest, the most important, meaningful battle for LGBT rights is being waged over a different kind of law: a civil rights measure that explicitly makes it illegal to discriminate against people based on their sexual orientation or gender identity.

Indiana has no such law, and Pence has made it clear that making LGBT people a protected class is not on his agenda.

It's not religious freedom laws that allow discrimination; it's the lack of civil rights laws

Most states, including Indiana, have long allowed anti-LGBT discrimination because they don't have civil rights laws that would prohibit discrimination against LGBT people in the workplace, housing, and public accommodations (hotels, restaurants, and other places that serve the general public). In these states, it's not religious freedom laws that allow discrimination; it's the lack of civil rights laws.

Currently, 19 states ban discrimination based on sexual orientation and gender identity, while three additional states ban discrimination based on sexual orientation. Some other states protect public but not private employees. And many municipalities have nondiscrimination laws that only apply within their local borders.

The protections sometimes vary from state to state. Massachusetts's protections for gender identity and Utah's protections for sexual orientation and gender identity don't apply to public accommodations. Some states, like Utah, also include exemptions for discrimination based on religious grounds.

Advocates argue the Civil Rights Act of 1964 already protects LGBT workers from discrimination, but that interpretation of the federal law hasn't been proven in court.

Indiana has no statewide nondiscrimination law for LGBT people, although about a dozen cities, including Indianapolis, have local measures.

"That's what's missing in the Indiana debate," Wilson of the University of Illinois said. "If there's a 'license to discriminate,' it's the fact that the state hasn't said this is an unacceptable basis for saying no to people."

Watch: How most states still discriminate against LGBT people

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