LSD was banned due to its association with the anti-Vietnam War hippie movement and perceived threat to the American status quo, not solely on evidence of harm.

“and then the dea come in and cia come and say we've got about it he's saying what we're talking about and of course what they were talking about was was the fact that the hippie movement was starting and the hippie movement was anti the war in vietnam and lsd was seen as fueling the hippie movement”