Image © Austin Cline, Licensed to About; Original Poster: National Archives
A major subject of the ire of Christian Nationalists is homosexuality -- in particular, efforts to protect gay Americas from discrimination on the basis of their homosexuality. Conservative evangelical Christians profess to "love" gays and only "hate" their sin of homosexuality, but for some reason their "love" doesn't translate into refusing to discriminate against them or refusing to treat them as inferior, second-class citizens.
Christian Nationalists claim that being prevented from discriminating against gays would infringe upon their religious and civil rights, a position beset with fatal problems. It assumes that actively discriminating against gays, rather than just expressing disapproval of homosexuality, is required by their religion. Even if this were true, they also assume that they have a religious liberty interest in discriminating against gays which is more important than gays' civil liberty interest in being treated equal under the law. Finally, it assumes that there is something about homosexuality which justifies such a position even though this argument would never even be made, much less taken seriously, if the targets of discrimination were Jews, women, or blacks.
It's important to remember what the opposition to laws protecting gays from discrimination really means. These laws would prevent people from discriminating against gays when renting apartments and selling houses, so Christian Nationalists support the ability of bigots to deny gays fair housing. These laws prevent people from firing and refusing to hire, promote, or give bonuses to people just because they are gay, so Christian Nationalists support the ability of bigots to deny gays equal jobs and wages. These laws prevent people from refusing to provide medical, legal, accounting, and other basic services to gays, so Christian Nationalists support the ability of bigots to deny gays the same services everyone else takes for granted.
The image above is based upon a World War II poster describing "Willful Absenteeism" as striking at our liberty. It's disturbingly similar to the "Stab in the Back" myth which helped animate support for the Nazis and other far-right nationalists in Germany. Christian Nationalists today seem to view support for the equal rights of gay Americans as a betrayal of American principles and an assault on freedom -- their freedom to discriminate.