Probably more of an actors wearing currently popular hairstyles while filming period shows. I think there must be examples of movies set in olden times, filmed in the seventies-eighties, where the actors have feathered, layered haircuts.
Looks like a neo-nazi cut
The show (Boardwalk Empire) is pretty good. Not top tier but pretty watchable. If you have HBO streaming give it a try.
Just fashion. I have a hundred year old photo of my teenaged grandfather with the same cut. (In rural PA)
I go to a neighborhood barber shop, run by well… hipsters… cashing in on the retro-barber shop experience but you know… a bit dirty and lots of tattoos and music you’ve never heard of before. Stereotyping aside, I enjoy the heck out of the atmosphere and banter of the guys in the shop. After 20 years of going to a “hair stylist” in a salon, this is a refreshing change. However… I think 99% of their haircuts is the side-part fade. While I’m waiting, I can look across a row of 5 chairs with customers and every. single. one. is a side-part fade (and beard trim of course).
I personally don’t know a single military man or veteran who would wear his hair like that. High and tight as it’s meant to be, yes. With all that length on top, no.
My high school cross country coach was a Marine colonel. A parent asked him to dinner and he replied that he had to get his haircut. She asked if he could come next week, and he said he had to get his haircut then, too. No one thought it was a dodge.
To assume that every man with this hairstyle is “Alt-right” is silly. People should judge a man by the content of his character, not the cut of his hair.
People from my era called them whitewalls.
I agree. I think the farther elements of the right are deliberately trying the blend in with the general population more than usual. The undercut is a common, practical and versatile cut that looks pretty good. You’re going to stand out much less with this and a polo shirt or suit, than as a skinhead covered with swastikas. The undercut wiki article with Richard Spencer looks like pretty much every other guy in the mall.
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This, cut, or a very similar variant, seems to become particularly fashionable once a generation or so. Like many other fashions.
Even if a Neo Nazi straight up admitted he did it to look like a Hitler Youth, well, the cut was practical and common back then too.
Yes, I’ve heard/seen the cut called a ‘jugend’ because it looked like a Hitler Youth cut…long before the recent alt-right guys pitched up with it. I think it started a bit niche, showed up in the media (Boardwalk Empire, Peaky Blinders) and has now filtered down. Maybe it’s hanging on with the new-nazis now because it looks pseudo-military and goes with the camp, khaki and leather?
On the way out? Who knows? Fashion is cyclical.
Q: How often does a Marine need a haircut?
A: A good Marine never needs a haircut.
Yeah, you got it. Back in the day, guys with them usually sported haircuts like a “Detroit”, which was a longish style with a duck’s tail. The shaved sides made the cut’s name work. Kids.
I may have changed my mind on the ugliness of this haircut. I was watching ‘In Search of’ with Zak Quinto. It looks damn good on him.
If I tried to do this sort of haircut, I’d essentially be completely bald.
It looks to me like someone couldn’t decide whether he wanted regular hair or shorter hair, so he tried both at the same time.
Maybe it should be renamed the “telluM”. 
Maybe it should be called the “Reverse Picard.”