That they are largely leftist is hardly a surprise - The largest population of Jews until very recent times, was found in New York City. They tend, as a people, to be city dwelling, and urban areas are almost always infected with liberalism.
That does not make them wrong on this subject.
And as to your major point - 'Holocaust-muzzle' laws are largely enacted as a knee-jerk reaction to a vile, intentional, and organized historical revisionism. Were it not for the Jews, even now, we would not remember - I guarantee it. And it is an important thing to remember clearly. Them that don't remember will do it again.
Not long past, the Catholic v. Protestant Irish kerfuffle spilled over into American politics and city life.
That is almost categorically false. Western academia and journalism almost invariably carry a pro-muslim bias, and that is being kind.
It has been a while, but what was 'clearly stated' in Mein Kampf has little to do with the truth. Hitler's organization was informed by ancient Germanic gods, and was deep in occult practices. To attempt to blunt the religious aspect of that war, is nothing short of a blatant denial of reality.
It is an interesting point about the urban vs. rural residence, and of course we can never prove what really causes so many of them to be liberal. It seems to me that, in the US, they have latched on their special interest to many other special interests, in the form of the democratic party.
Yes, it does not necessarily make them wrong on all subjects, but as stated I feel that it is ethically wrong to try to punish other's opinions, which is why I am against such laws, and I am skeptical of any "truth" any such organizations put out.
I think it's quite a stretch to say that the Holocaust would be forgotten if not for the Holocaust-proclamation machinery operating constantly as it does.
The Washington Times, NY Times, CNN, and the like do have a pro-Muslim bias in many cases, when it is a matter of Muslims vs. Christians. It's a way for them to oppose Christianity. However it seems to me that nothing compares to their Jewish/Israel bias, as recently displayed in their response to the embassy move. You have Fox that like many here supports Israel because they see it as an partner of Christianity. Then you have the rest that like Israel because many of them are Jewish, or at least the ones pulling the strings are. Atheists, fake Christians, and Jews, there are many. As for true Christians, there are few. I'm not saying that someone like the Fox contributors or you guys who support Israel are not true Christians, just that I think you should adjust your approach and acknowledge more often that we are playing their game when we support them easily or even blindly. Examples: Nikki Haley, the guy who recently told Carlson that we should go to war "if you care about Israel" even though it doesn't benefit the US in any way.
The fact remains that Hitler clearly stated that he wanted to persecute Jews only based on race and not at all because of their religion. Whether that is what was really in his heart, or the hearts of the ones who liquidated them, is a long-standing historical question. The point is that whether or not the Jews are a race in terms of the classifications that you respect, they have been treated as a race before and continue to be treated as one at times even today.