I've never heard of McKinley as a first name until now. It seems to have been invented around the same time that President McKinley became well known. It was almost exclusively a boys name until suddenly, around 1970, people started naming girls McKinley. Today 90% of babies named McKinley are female.
We were friends with a man whose first name was Wilson, and to make it really confusing his surname was a common male first name - something like "Wilson Mike" - not his name, but you get the idea. When getting official forms filled out the secretary or registrar would ask him his name and when he answered they thought he was giving his surname first and they would nearly always switch it around to Mike Wilson when they typed in his name.
My seventh grade English teacher would say, "Behind the at." (I never really understood many of her sayings but at least she tried to set us straight on grammar.)
If you can find this movie and its sequels, it's a very fun watch: https://www.zilnikzelimir.net/kenedi-goes-back-home The protagonist's father named his Roma boys after US presidents so that they'd have better chances in life: Kenedi, Džonson, Nikson (Serbian phonetic spelling)
I'm pretty sure that's the same Kennedy (full name: Lisa Kennedy Montgomery) who was formerly on MTV. She's an unaffiliated libertarian; her embracing of neoconservatism has varied over her career. But, generally more conservative than one would expect on MTV, at least back then.
I would love to see a list of worst presidential last names to give your child. Intentionally excluding the last twenty hears, here are my top three: Hoover, Fillmore, Polk.
Grant - 1,980. There are an estimated over 111,000 Grants in America - this one is trending downward
Hayes - 1,227. Who names their kid Hayes?
McKinley - 679. Personally I thought this one would have been higher on the list
Monroe - 618. This is by far the most unisex names of all the top 15, ~61% are males.
Pierce - 609. I could see this one being a baby name but, like Hayes, I don't know of any Pierces.