Trump delivered in Atlanta a rejoinder to VP Kamala Harris’ high-energy rally 4 days prior. He disparaged Harris calling her “dumb” and “low IQ.” Harris who has a law degree, served as a District Attorney for San Fracisco and later elected as Attorney General of California, an accomplishment difficult to attain with a "low IQ". Trump on the other hand is not known for any intellectual achievements but as a fraud, a rapist and a convicted felon.
https://www.rawstory.com/news/trump-atlanta-rally/