A new era of political violence is taking hold in America - How violence became a theme of America's election - The U.S. has had a long history of political violence, but experts see a new trend - Rep. Lisa Blunt Rochester on U.S. political violence - Political violence becomes America's new norm - but is still shocking - How Americans Justify Political Violence - Comparing the history of political violence in America and the UK - Violence plagued all levels of American politics long before the attempt on Trump's life - 'Political violence in the US is linked to a history of conquest and predation' - Despite appeals for peace, the U.S. has a long history of political violence