DePaul has tied itself in knots over how to respond to conservative student groups trying to bring provocative speakers to campus. A May appearance by right-wing bad boy Milo Yiannopoulos ended in a melee when audience members shouted him down and someone grabbed away the microphone. School officials denied a request to bring him back this fall and also vetoed an appearance by another conservative commentator, Ben Shapiro. Both are showmen who revel in getting under the skin of liberals. DePaul administrators said they needed time, lots of time, to contemplate how to react to the infiltration of potentially unpopular notions.