"We don't live in a dictatorship or monarchy. I swore an oath - in the military and in the Senate - to preserve, protect and defend the Constitution of the United States, not to mindlessly cater to the whims of Cadet Bone Spurs and clap when he demands I clap," Duckworth wrote in a tweet, using a nickname she had given Trump, who had said in previous interviews that he was granted medical deferment during the Vietnam War after he was diagnosed with bone spurs in his feet.