Looks like it flipped in ~the 40s, by the ~60s had become rarer as a male name, and was pretty much a flop as a male name after the ~80s. So Clinton was born just when it started to take off for females (and in general - it was never as common as a male name) and there should have been in the same ballpark as as many male "Hilary"s of the same age.
https://namedaisy.com/us/name/Hilary