Origin of usage: "hardcore"?

I was talking to a bunch of my Valley Girl friends, and started wondering where the oft-used term “hardcore” comes from. A search at the OED yields a bit from 1851 about stuff used as filler for construction, and parts of fruit, but doesn’t really help me with modern usage of the word to convey the utter rockin’-ness and general radical nature of the thing described.

As a regional narcissist, I suspect that “hardcore” was used to describe pornography, and since porn is one of the Valley’s major exports, we kids couldn’t help picking it up. But I know young people in other places say that things are hardcore, too. What gives?

Merriam-Webster shows it showing up in 1936.

Bolding mine.

Right. That works for hardcore punk rockers. But I have sweaters that have been described as “totally hardcore,” and they have no devotion to any political causes at all. There aren’t even slogans printed on them. That’s the usage I don’t understand.

I guess I should just chalk it up to dumbass kids who use “tubular” as a compliment. But I wish there were some sort of rhyme or reason to this teenage slang business.

Does “tubular” come from the song “Tubular Bells”, that (at the time) cool instrumental song from the 1970’s?

It might’ve been revived by Tubular Bells, but Jesse Sheidlower claims that “tubular” hails from the 1960s.

I always figured “tubular” was a surfing term, since a wave forms a tube that you can surf inside.

I think the use of “hardcore” as it’s applied by teens to items such as clothing only occurred in the 1990’s, and probably the late 1990’s.

The Random House Dic of Hist. Am. Slang for “H” doesn’t show that usage, and it was compiled mostly in the 1990’s with a publication date of 1997.