Not sure if I'd consider emo or goth "underground". The Cure and similar bands were very popular in the early 80's. Grunge and emo overshadowed them, and now Black-inspired music is arguably the norm for the mainstream.
It's always been the norm. The Beatles have skiffle roots, The Rolling Stones were inspired by black blues and early rock artists, early British hard rock is Delta blues-inspired, Elvis and Jerry Lee Lewis (who in turn inspired artists like Elton John) were pioneers in bringing black music to the white masses, even racists like Ted Nugent admit their primary influences were black.
Any genre associated with independent record labels is basically underground, which definitely includes emo. White people go underground when they get sick of the sh**ttiness of white music.