Update: On Thursday, Arkansas passed a revised religious freedom law that critics say could allow discrimination against LGBT people in the workplace, housing, and places that serve the general public, although legal experts doubt these laws will actually have this effect, based on decades of legal precedent from court battles involving RFRAs.

On the same day, Indiana Gov. Mike Pence approved a clarification to the state's controversial religious freedom law 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 laws are part of a broader movement across the country: as marriage equality continues its spread from coast to coast, LGBT advocates and opponents are pushing conflicting agendas that could have a major impact on the rights of LGBT residents.

19 states protect LGBT workers from discrimination

LGBT nondiscrimination protections add sexual orientation and gender identity to existing civil rights laws that already shield against discrimination on the basis of race, national origin, and age in the workplace, in housing, and in public accommodations (hotels, restaurants, and other places that serve the general public).

The map above doesn't cover all the protections in the US. Some states protect public but not private employees. Some municipalities have nondiscrimination laws that only apply within their local borders. 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.

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, including Utah, also include exemptions for discrimination based on religious grounds.

These states have passed nondiscrimination laws since the beginning of 2015:

Utah: On March 12, Utah Gov. Gary Herbert (R) signed a law that bans discrimination based on sexual orientation and gender identity in the workplace and in housing. The law includes major exemptions, such as provisions that let religious groups and their affiliates continue to discriminate against LGBT workers.

At least 22 states have laws that critics say could limit LGBT rights

In recent years, lawmakers have introduced various bills and laws that could restrict LGBT rights. Here are some of the most popular proposals:

Religious Freedom Restoration Act (RFRA): These measures prohibit governments from infringing on a person's religious beliefs without a compelling interest. Critics say individuals and businesses will be able to use these laws to bypass civil rights protections for LGBT people in some cities, although legal experts doubt these laws will actually have this effect, based on decades of legal precedent from court battles involving RFRAs. Religious freedom law for adoptions: These bills and laws allow adoption and foster care agencies to refuse to participate in placements if they have a religious objection, potentially allowing them to discriminate against would-be LGBT parents. Nullified local civil rights protections: This legislation prevents municipalities, such as cities and counties, from passing laws that protect LGBT people from discrimination in the workplace, in housing, and in public accommodations.

A March report by HRC found that lawmakers in at least 28 states have proposed a wave of bills that could limit LGBT rights. Most are unlikely to pass — state legislators often introduce proposals that never see the light of the day.

Since the beginning of 2015, these states have passed laws that could limit LGBT rights:

Arkansas : On April 2, Gov. Asa Hutchinson (R) approved a religious freedom law that critics say could legally protect discrimination based on religious grounds against LGBT people. Previously, on February 25, Hutchinson allowed a law to take effect that prohibits local governments from establishing their own nondiscrimination protections for LGBT people.

: On April 2, Gov. Asa Hutchinson (R) approved a religious freedom law that critics say could legally protect discrimination based on religious grounds against LGBT people. Previously, on February 25, Hutchinson allowed a law to take effect that prohibits local governments from establishing their own nondiscrimination protections for LGBT people. Indiana: On March 26, Gov. Mike Pence (R) approved a religious freedom law that critics said could legally protect discrimination based on religious grounds against LGBT people. But on April 2, Pence approved a clarification 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.

Watch: How most states still discriminate against LGBT people