The Red Scare was by its nature a temporary sense of hysteria, so I think it is likely to burn itself out, after a short period of time, maybe there would be longer term legislative effects of it that continue way beyond, but the scare itself would not last.
I think what is more likely is a third red scare taking place in the 1980s. There was one after WW1 after the Soviet Union was formed, another after WW2 as it expanded, logically the heightened tensions of the 1980s could have led to another one, perhaps if America had a more prominent radical left, as Britain did at this time.