text:  A national survey conducted by the Chicago Project on Security late last month showed that 10% of American adults, or about 26 million people, agreed that the use of force was justified to prevent Donald Trump becoming president. That survey was led by Professor Robert Pape, who's a leading expert on political violence in the US and who joins us now live. Professor, welcome. In the light of your research, you won't be entirely surprised by what's happened.