But others, including executives at several large companies, say Republican Gov. Phil Bryant's decision to sign the bill amounts to discrimination, even if they find same-sex marriage morally offensive.
It's a debate that has played out across the U.S. after the Supreme Court effectively legalized gay marriage. It has intensified since Georgia's governor vetoed a similar proposal, and since North Carolina's governor signed a bill that bans cities from enacting anti-discrimination ordinances and requires transgender people to use public bathrooms that conform to their sex at birth.
One law expert said Wednesday that parts of Mississippi's law may violate the First Amendment by favoring particular religious beliefs. He warned other parts of the law may violate the 14th Amendment's requirement for equal protection by imposing a stigma on same-sex marriage.
"This violates their constitutional rights in so many ways," said George Cochran, a constitutional law professor at the University of Mississippi. He called it a "nasty, vindictive piece of legislation."
"This is open season on LGBT groups," Cochran said. "I don't think this bill left out any way to discriminate against them."
Still, some say the law is necessary to protect their beliefs.
"I feel like while you can't take rights away from one person, you can't take rights away from someone else," said Jennifer Hazlewood, a 40-year-old Brandon resident. The stay-at-home mom said she felt the law was needed because traditional Christian values are being eroded. "Our rights to believe the way we believe, I don't feel are protected."
Others said the law is a license to discriminate.
"I feel like it's wrong to turn down someone for service because of their sexuality because it makes them feel unimportant, and more important, it makes them feel like they're not worthy of being an American in the same place as everybody else," said Tyler Willis, a 22-year-old Wal-Mart worker from Pearl.
Mississippi's law would, for example, allow a church group to decline housing or adoption services to gay couples. Private businesses could refuse marriage-related services such as room rentals, cakes, photography or flowers. Any employer or school could refuse to allow a transgender person to use the bathroom of their choice.
Among government employees, clerks could refuse to issue marriage licenses and judges could refuse to marry gay couples. In both cases, governments are supposed to make sure the license and marriage are "not impeded or delayed." Supporters say that in any county where all clerks opted out, clerks could hire special deputies.
Attacks on the law mounted Wednesday. The only Democrat in Mississippi's congressional delegation asked U.S. Attorney General Loretta Lynch to sue to block the measure, saying it would give people "the explicit right to discriminate against anyone with a lifestyle they disagree with, in the name of religion." A spokeswoman for Lynch didn't immediately respond.
Executives for General Electric Co., Dow Chemical Co., PepsiCo Inc., Hewlett Packard Enterprise, Hyatt Hotels Corp., Choice Hotels International Inc., Levi Strauss & Co. and Whole Foods Market Inc. called for the law's repeal in a letter released by the Human Rights Campaign, a gay-rights group.
Supporters, though, say First Amendment protections for freedom of religion should trump all those issues. Supporters liken the law to others that allow people to opt of out providing abortion services.
"The right of conscience is a fundamental right," said Matt Sharp, legal counsel for Alliance Defending Freedom, an Arizona-based group that advocates for legal views that advance Christian beliefs. "That right has to be protected, and sometimes it can result in an inconvenience."
Mississippi Attorney General Jim Hood, a Democrat, said he'll make "case-by-case" decisions on whether to defend the state against lawsuits, warning that the bill doesn't override federal law or constitutional rights.
"If a person or government official violates a federal statute or constitutional provision, House Bill 1523 will not protect that official from a federal lawsuit or from potential personal liability under federal law," Hood said in a statement.
Online: House Bill 1523: http://bit.ly/1qo4guX
Associated Press writer Nassim Benchaabane contributed to this report.
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This story has been corrected to remove attribution to Phil Bryant regarding a remark about business pressure showing the need for the law.
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