Donald Trump has been fueling his presidential campaign with a combination of racist fear-mongering and fascism, but the businessman and Republican primary frontrunner has had an ugly past few days, even by his standards.On Saturday, several white men at a Trump rally in Alabama beat a black protester , and Trump said the victim deserved it. A Black Lives Matter activist disrupted the event, and a mob of people swarmed him; video of the incident shows the men kicking the protester while he is on the ground. Security removed the man from the conference center.When asked about the incident on Sunday, Trump said, “Maybe he should have been roughed up."Trump also started Monday by retweeting a graphic filled with made-up statistics about crime. The graphic — which apparently originated with a Nazi supporter — says that 97% of murders involving Black individuals are committed by people of the same race. That figure was actually 90% in 2014; more than 82% of murders involving white victims were committed by other white people. "Black-on-black crime" is not substantially more common, no matter what opponents of Black Lives Matter activists say.This is only the latest in a string of disturbing incidents and statements from the GOP front-runner. On Thursday, Trump told a reporter from Yahoo News that he wouldn't dismiss the idea of forcing Muslims to register in a database or carry a special ID. Even when he tried to clarify himself, Trump doubled down on ugly sentiments. He told a crowd on Saturday that he wants widespread surveillance of mosques and a database of Syrian refugees , and he said he wants to bring back waterboarding — a torture technique used on suspected terrorists that has produced no valuable intelligence.