While I cede that it was not first used by the KKK, you must admit that it was indeed used by them and groups tied to them throughout history. If you would like I could include sources showing the initial usage in 1920 during the time of Woodrow Wilson. The slogan during this time also had issues with many proto-fascists and anti-Semites [1] 2. 3
I hope you take the smithsonian and 2 articles written 10 years before Trump's 2016 presidential run as valid unbiased sources, unless you think they somehow could read the future.
Secondly, the question is not closed ended. It has follow ups for that reason, if yes, then does the yes also pertain to other slogans containing similar historical content?