Yes.
The gay men will make up for it. Many more gay men than women.
Say what? That’s no more true than saying that legal same sex marriage means that gay men will kidnap other men off the street for sex slaves.
Yeah, I can see it. I sure wanna fuck a lot of chicks.
Those gay men are already out of the pool. And they *ahem *service themselves. 
Well I’m not saying they’ll do it by force. They’ll just make it attractive enough for lots of hoochies to sign up for Harem duty.
No.
But good for you for giving the Expert a lifeline.
What word would you propose to describe a person who wishes to enter into a marriage with two other people at the same time but cannot because the law forbids it?
Yes and no.
Technically, as mentioned earlier, you could slice and dice humans into any number of classes (e.g. people who play paint ball).
As regards Equal Protection it is my understanding a “class” needs to meet particular criteria.
As such polygamous people and paint ball players, to name two, are not a “class” under an EP analysis (their characteristics are not immutable).
I doubt it. Women can do that right now, they just can’t all marry him. And some in fact do. Making polygamy illegal isn’t what largely killed the old rich-men-have-harems setup; that just meant that rich men went from having harems of wives in harem buildings, to having lots of female “servants” who just happened to all live in “servants quarters” with a door to his bedroom. It was making it mostly socially unacceptable, which changing the law won’t do anything about.
Missed edit:
I am guessing “class” in the OP, when talking about an EP analysis, really means “suspect class”. Polygamists are not a suspect class.
True. Polygamists are not a suspect class.
That’s exactly what I said to Diogenes:
That’s no different from rich men who cheat. Oh wait: Mistresses aren’t afforded any protections. 
Sounds like you two are talking past each other.
A “class” of people can be anything you like.
(For the following I am not lecturing you, I am sure you know it better than me, just laying out the thinking of where you two might be missing and for other readers.)
For most classes EP analysis applies Rational Basis which, as I understand it, means the state can discriminate against that class for pretty much any reason they can put words to. The bar is so absurdly low as to make it almost no bar at all. If the state wants to ban paintballs then they can ban paintballs.
Past Rational Basis we get Intermediate and Strict Scrutiny which are much higher bars to cross and the state had better have some good reasons for discriminating against those people (especially for Strict Scrutiny). These are the “protected” classes. For this what I posted above is applied.
So, it is quite possible to say paintballers are not getting Equal Protection but I think the Supreme Court would answer, “Yeah. So what?” Same for polygamists. They need not be defined as a protected class to have someone say they are being denied equal protection. The courts just won’t care because they fall under the Rational Basis test as they do not meet the requirements for more stringent scrutiny to be applied.
Ack…missed edit window again and forgot to add:
It seems you and Dio might be using “class” both as shorthand for “protected class” and just “any old class (i.e. group) of people” you can conjure up. Mix and mash and confusion ensues.
Technically, I guess, “any old group of people” is a class for EP analysis but as mentioned Rational Basis is such a low bar as to make it a distinction barely worth making.
These are arguments for why polygamy should be legal, but do not address the class issue.
The nature of the class is irrelevant. The fact that they are a definable group of people make them a class. They are not a suspect class for a variety of reasons, but any defined group of people are a class.
As for the existence argument, it would be true that there is no class of people with legal marriages certificates with more than two spouses on them, but there is both a class of non-recognized polygamists and a class of those who desire to enter polygamists unions.
Until the nature of society is much more gender neutral, more men will have harems than women. Both because more men are in a position to do and more women will be willing. And, as with many things, once it becomes legal it will start to become socially acceptable.
They’re talking past one another all right, but in a slightly different manner. I think they both know the differences between class and protected class, but Dio’s point is you can’t have a class made up of nonexistant entities. Since a polygamist is someone who is married to more than one person, and since you can’t be married to more than one person in the US, therefore there are no polygamists in the US and there is no polygamist class, protected or otherwise.
I don’t know who’s right, but frankly it seems like a pretty pointless debate. They might as well be arguing about whether or not centaurs are a class.
That’s unclear at this point in time, I think. There are plenty of polyamorists (yours truly included) who believe that, exactly like gay people are born and immutably gay in orientation, although may not be in behavior, at least some polyamorists are born and immutably poly in nature, if not behavior. (I do acknowledge that for some, it’s an intellectual decision, or one made to appease a partner(s), but IME, those are the ones for whom things usually end badly. And the same applies to some people who experiment with gay sex through force of intellect or to please a partner.)
I’m a poly woman in a monogamous relationship by choice. I choose not to engage in poly behavior because my partner is monogamous, but I still feel and identify as a polyamorous person. ETA: I don’t see how it’s fundamentally different from a lesbian woman partnering with a man out of choice; she may not be having lesbian sex, but she’s still a lesbian.
How can you say that in the face of this exchange?
Doesn’t that make clear I am not using shorthand at all, since I clearly differentiate “class” from “protected class?”
Doesn’t that make it clear that he is also aware of the difference and is saying that they are not a class, perioid…NOT that they are simply not a protected class?
I’d use the word “polygamist.” But I can’t figure out why you asked me that question.
Your cite says, “To be considered a suspect classification …”
You then go on to say that paintball players are not a class because their charateristics are not immutable.
Don’t you mean, “They are not a PROTECTED class?”
Where did you get the idea that every class must have immutable charateristics?
Polyamorus is not the same as polygamous. Polygamy is against the law. Polyamory is not.
Even if you want to grant them protected class status that status does not preclude discrimination. No right in the constitution is absolute (e.g. your right to Free Speech is not absolute and there are restrictions on it). The courts need to decide where appropriate lines can be drawn and if the state can show a compelling reason to restrict a right to a group then it is possible to do so (or frankly nearly no reason at all for Rational Basis). The higher the level of scrutiny the harder it is for the state to show a compelling reason (and in the case of Strict Scrutiny the state must tailor the law to be as narrow as possible to achieve the desired result).
In this thread running in GD now I spell out reasons for why I think polygamy is a bad idea and the state has a compelling reason to ban it.
That said, and I want to be clear on this, I am personally perfectly fine with polygamy if all the adults are up front about it and ok with it as a lifestyle choice. I just think it is unworkable and produces far more troubles for society when looking at the legal issues surrounding it (e.g. what happens in a divorce) to make it well within the state’s interest to ban.
If you can solve those problems (not sure how but go for it) then I am fine with it. Knock your socks off.
Because you suggested that “polygamist” had a narrow definition.
If a polygamist is someone who wishes to enter into a plural marriage but cannot because the law forbids it, then we analyze his equal protection claim as affecting the class of polygamists. As this class is not protected, we would use the rational basis test.