http://www.youtube.com/watch?v=NM51qOpwcIM
^Stephanie Germanotta may have been able to be popular in earlier times. However, I don't think Lady Gaga would have been able to make it in the 50s (too shocking attire and whatnot).
If Little Richard made it, I can't see why Gaga could not. The lyrical choices may have to change, and the music itself would be so far out at the time as to be considered ear torture, perhaps, but the costumes would have been taken well by the youth. Outlandishness was in and it was simply a lack of original context that prevented some Ziggy Stardust shit from happening in the post-war west. Particularly playing up the Cold War Era sci-fi element of her wardrobe concepts, (imagine George McFly's wet dream on Bandstand...) yeah, it would work.
This brings up an idea I had that I mentioned in another post: It would not have been too much of a stretch for a drummer in England in the late fifties or early sixties to begin drumming in rhythms and beats similar to Franz Ferdinand, of Montreal, Two Door Cinema Club, The Rapture, etc. Four on the floor, dance beats behind proto-power pop/rock 'n' roll music.
What if the "Mersey Beat" had been sped up, kick drum on every beat, sixteenths on the hi hat in nature? The birth of dance rock at the dawn of the sixties... This HAS to have some intense musical and cultural butterflies for decades. It could be pretty well accepted too, I don't think it's much of a stretch.
http://www.youtube.com/watch?v=7QC-s6e1jWI