Donald Trump, the presumptive Republican candidate, escaped an attempt at his life at a campaign rally in Pennsylvania on Saturday. Although authorities are working to determine the motive behind the shooting, the incident comes just a month after a survey found rising support for political violence in the country. What Happened: Ten percent of those surveyed said that the “use of force is justified to prevent Donald Trump from becoming president,” a nationwide poll conducted by University of Chicago political scientist Robert Pape in June showed. A third of those who responded with the answer…