Washington (AFP) – The US election debates commission on Thursday turned down the Trump campaign’s push to add a fourth televised clash with Democratic challenger Joe Biden.The commission said that “three 90-minute debates work well to fulfill the voter education purposes the debates are intended to serve… (and it) remains committed to the schedule.”The first debate will take place September 29 in Cleveland, Ohio.The event will inject drama into a presidential contest that has so far taken place largely online, as both candidates operate under the restrictions of the coronavirus shutdown.Pre…