Please quote the Constitution where it says that any race is a protected class.
They're not called deviancy laws. They're called decency laws. They regulate public activity not private activity. The state has no authority to regulate the private activity of consenting adults which infringes on no one's rights.
When arguing for protected class you appeal to individual rights. Again that's self contradictory. I think you need to google group rights and protected classes.
I didn't argue that homosexual activity is not the defining characteristic of homosexuals. I said it's self contradictory to state that homosexuals are a protected class but the only activity which defines them as such is not protected.
The First Amendment does not protect particular activities of religions, just religion in general, is the same as saying homosexuals are a protected class but not homosexual activity.
If you're familiar with the Italian Philosopher Cesare Beccaria, who wrote "On crimes and Punishment" he argued for the responsibility of Civil Government to define both the nature and parameter of "deviance"
From "on crimes and punishment"
Beccaria’s Theory:
There are three main legs in which Beccaria’s theory rests. Those are that all individuals possess freewill, rational manner and manpulability. Beccaria, like all classical theorist, believe that all individuals have freewill and make choices on that freewill. The second leg, rational manner, means that all individuals rationally look out for their own personal satisfaction. This is key to the relationship between laws and crime. While individuals will rationally look for their best interest, and this might entail deviant acts and the law, which goal is to preserve the social contract, will try to stop deviant acts. This ends up with the individuals and the society rationally looking for satisfaction, and at times these interests clash. The third leg in which Beccaria’s theory rest is manipulablibily, universally shared human motive of rational self-interest makes human action predictable, generalable and controllable. (Roshier, pg.16). The job of the criminal justice system is to control all deviant acts that an individual with freewill and rational thought might do in the pursuit of personal pleasure. This is made easier by the fact that human actions are predicable and controllable. With the right punishment or threat the criminal justice system can control the freewilled and rational human being. The problem the criminal justice system has is finding the right punishment or threats"
'On Crimes and Punishments" had a large and lasting impact on the American Constitution, the Bill of Rights and our criminal justice system.
So the question is can Government both define and enforce "deviant" behavior?
Case law confirms is not only possible, but implemented:
http://legaldictionary.net/deviant-behavior/
https://definitions.uslegal.com/d/deviate-sexual-intercourse/
http://www.people.vcu.edu/~jmahoney/deviance.htm#Definition_of_Concepts:_Deviance_and_Cri
Then is Homosexuality considered "deviant" behavior?
Homosexuality was defined as not simply a matter of sexual desire or the act of sex, but as a dangerous quality that defined the entire personality and moral being of an individual (Foucault 1980). From that point until the late 1960s, homosexuality was regarded as a deviant, closeted activity that, if exposed, could result in legal prosecution, moral condemnation, ostracism, violent assault, and loss of career. Since then, the gay rights movement and constitutional protections of civil liberties have reversed many of the attitudes and legal structures that led to the prosecution of gays, lesbians, and transgendered people. The point is that to whatever degree homosexuality has a natural or inborn biological cause, its deviance is the outcome of a social process.
Source:
https://opentextbc.ca/introductiontosociology/chapter/chapter7-deviance-crime-and-social-control/
You wrote:
"The state has no authority to regulate the private activity of consenting adults which infringes on no one's rights"
This is not always correct because certain private activity can be deemed to be deviant and thus the State can and does restrict it as those links I provided showed they often do. Individual rights are always protected under the Constitution and I never said they weren't, but engaging in homosexual behavior is an individual activity, not a right. Again, one cannot be a homosexual without engaging in homosexual acts. It is not a condition of birth, therefore it is not protected as a right like being human is. To the extent homosexuals are first human, they already have all of the rights afforded to human individuals under the Constitution, including their choice to commit homosexual acts.
Those choices though are not automatically protected under the Constitution as a matter of their status or class...it's simply a matter of their choice which is or can be restricted.