Despite being struck down in Kansas and vetoed in Arizona, proposed legislation granting businesses the right to refuse service to customers on the basis of their sexual orientation has been spreading across a number of states this week. As victories for gay rights leave conservative citizens looking for novel ways to fight back, the meaning of religious freedom is called into question. While the line between religious freedom and civil rights often seems like a matter of public opinion, both the enforcement of these laws—if any pass—and the fight against them face a number of institutional hurdles.

Religious and political factors have historically influenced attitudes towards gay marriage. Here’s how:

• Darren E. Sherkat, Melissa Powell-Williams, Gregory Maddox, & Kylan Mattias de Vries. 2011. “Religion, politics, and support for same-sex marriage in the United States 1988–2008.” Social Science Research, 40(1):167-180.

Public opinion may not be enough to change this kind of legislation, but controversy helps. State governments rely more on public conflict and issue salience as motives to act, and may be bad at protecting the LGBT population from job and housing discrimination “even when the public supports the pro-minority position.”

• Jeffrey Lax and Justin H. Phillips. 2009. “Gay rights in the states: Public opinion and policy responsiveness.” American Political Science Review 103(3):367-386.

Moreover, how good is the “gaydar” at these religiously inclined businesses? Sexuality is learned and performed in a wide variety of social situations, and identifying patrons’ sexual orientation might pose more of a challenge than lawmakers think.

• John H. Gagnon and William Simon. 2005. Sexual conduct: The social sources of human sexuality. Transaction Publishers.