The dangerous 1915 KKK reached its peak during the second term of Calvin Coolidge.
Your logic here fails so hard.
This is just as pathetic as what I've seen from many blowhard far right conservatives. I mean really pbrower, I didn't expect such a fail of an argument to be used by you.
Let me give you an example of what I'm talking about to put it into better perspective:
Nazi Germany reached its peak during the second and third terms of Franklin Delano Roosevelt.
Just because Group X grows the most while Leader A leads B country doesn't mean that Leader A is most responsible for the growth of Group X.
Here's another example (a bit more fun):
Progressive Rock reached its peak during Nixon's second term.
See, those two have little to do with each other, yet this is the kind of argument you are employing in the quote. The idea that Richard Nixon was responsible for the popularity of Progressive Rock is crazy, so is the idea that Calvin Coolidge is responsible for the rise of the KKK.
I tell you if James Cox or John W. Davis were presidents during this era the KKK would be just as strong, if not stronger (if Davis was president). I am not denying that the KKK was popular amongst Republicans in the Midwest, but their strength at the time was due to environment and not just because one guy sat in the Oval Office. The president is not f***ing god and can not dictate the direction of society, there are other factors present.