The objections to prostitution generally seem to come in one of two categories.
A: That it's wrong to have casual sex. (Even though casual sex is perfectly legal.)
B: That it's wrong to pay for sex at all. (Even though gold-digging, sugar mamas, sugar daddies, etc... are perfectly legal.) This often comes with "guilt by association" reasoning in the form of naming individual examples of prostitutes who were coerced (which isn't inherent in the job) or were desperate (which applies to many other jobs that are perfectly legal) but even if guilt by association were valid, this still doesn't establish whether the problem is the act itself or the criminalization, and therefore, for the purposes of this thread, it doesn't count.
For context, let's just establish one reality. If you're caught hiring a prostitute, you go straight to jail, you do not pass go, you do not collect $200.
In the United States, this ends in a notoriously brutal prison sentence, likely complete with beatings and rapes from other prisoners, followed swiftly by release into a society that neither hires criminals nor allows them welfare. Indignation to johns must be pretty intense among voters to drive such a response.
Nordic countries' criminalization of prostitution, though I disagree with it, is (relatively) less drastic. It doesn't warrant as high a standard of explanation, as it's more rehabilitation-centric and less deterrence-centric.
So when you consider the full context of the extent of prostitution's criminalization, and the fact that Nordic countries are generally more progressive, it's reasonable to presume it is about B to a greater extent; and A to a lesser extent; in Nordic countries than the United States.
This suggests contempt for casual sex to be an irreplaceable ingredient in the severity of indignation at prostitution. And yet, casual sex won't even net you a community service sentence. So without further ado, I want to present 6 things that I will compare and contrast with prostitution such that you can vote on which you think is more morally analogous to it, or less.
1. In any sexual relationship; monogamous or casual; it is nearly impossible for both partners to be of precisely equal sex drive. If one partner is more horny than the other, and the other is only willing to accommodate them in exchange for other favours, and these favours could in other contexts be exchanged for money, is that analogous to prostitution? (Margaret Cho has made this comparison too.)
2. More specifically, there are dating arrangements where people overtly admit it's about the money. (Sugar mama, sugar daddy, etc.) So this establishes a clearer intent to exchange sex directly for money. Is it the monogamous nature of the relationship that prevents it from being counted as prostitution?
3. Child support law establishes a debt; often an overwhelming one; on whichever of a woman's sex partners happened to be the one to impregnate them. Why wouldn't paying for sex, which pools the resources of everyone who has sex, be more morally defensible than just allowing everyone who took the exact same risk to not have to contribute a dime?
4. At bars, drinks are often offered with the implicit arrangement of having sex with the person who offered them a drink later on. Is this analogous to prostitution as well?
5. Porn is compared to prostitution by Family Guy. Is this loophole about the fact that it's on tape and presumably has less potential for abusive situations, or just the average voter's willingness to let them get away with it if they can watch?
EDIT: I completely forgot to mention a sixth.
6. Sex strikes. In the context of sex strikes, women claim to refuse to have sex with men until certain demands are met. (Presumably, males are not cut out for the reverse.) Is this not essentially logically equivalent to "I will have sex in exchange for these favours"?
